I am a Fly Fishers International Certified Fly-Casting Instructor. I teach fly casting in lakes or rivers. Additionally, I teach salt water casting techniques. This blog will be dedicated to fly fishing and fly casting. I will also write about rods and reels and whatever takes my fancy in the fly-fishing universe.
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https://everyjonahhasawhale.com/wp-content/uploads/2016/10/Fort-Pickens-1.-nov-2009-068.jpg15842376Jonas Magnussonhttps://everyjonahhasawhale.com/wp-content/uploads/2019/03/FFI_9846_Logo®_Casting_Instructor_CMYK-600x476.jpgJonas Magnusson2016-09-29 01:28:482021-07-14 12:32:14Every Jonah Has a Whale - You cannot buy a cast!
https://everyjonahhasawhale.com/wp-content/uploads/2016/09/DSC00263.jpg1127673Jonas Magnussonhttps://everyjonahhasawhale.com/wp-content/uploads/2019/03/FFI_9846_Logo®_Casting_Instructor_CMYK-600x476.jpgJonas Magnusson2016-09-22 15:36:522019-03-09 16:51:02Feedback from my clients
The wind is light and the sun is shining and I am floating across a gorgeous flat in South Andros. I am in the ready position on the bow of the skiff and the guide spots a big bonefish. It always is a big fish but this one was huge – when it tailed we thought it was a sailboat. The sun was right – the wind was right – what could go wrong? My cast was perfect – I led the fish correctly (got the fly across the fish’s projected path) and bumped it into his field of vision when the guide said “strip it once” and the fish took the fly immediately and instantly bolted. I cleared the line and raised the rod tip a tad to cushion the line/leader when the line was pulled tight. You know where this is going eh? Yes, you do ……. the leader to tippet knot snapped instantly with a bang. This is a moment when adult diapers could be useful but I managed not to disgrace myself. Would you believe me if I told you that this happened twice the same morning?
Tackle failure; In both instances, it was the leader-to-tippet connection that failed. This has not happened to me before so I tied some more leader tippet connections and Capt. Baz snapped them easily. This will happen when the knots aren‘t pulled tight and I mean tight. As we glide down the razor blade of life our muscle strength diminishes. Years back I broke my right underarm (so-called Galeazzi fracture). It got fixed with a plate and screws but after that, I had a bit less sensation in the pad of my right thumb. Then onto the arthritis of the base joint of the same finger that led to an operation where the joint and the trapezium bone is just removed plus some fancy tendon plastic. All this wear and tear has left me with a weakened thumb. Now I must wrap the leader and tippet around my hands to be able to pull those knots tight enough. When I redid my knots this way the connection held. Capt. Baz helped me with this diagnostic work and remedy and even donated leather gloves to the cause of protecting my hands. After discovering this issue I did not have any breakage. Needless to say that the fish snapping the leader to tippet connection was much bigger than the eight-pounder I finally caught.
It is easy to get to Mars Bay and we left from Ft. Lauderdale flying straight to Congo Town on South Andros.
There it is – the landing strip of the Congo Town airport. At last, we were able to make this long-awaited trip to Andros. This trip was slated for the year 2020 but understandably got moved to 2021. There were some basic requirements – you must be vaccinated – you must provide a negative Covid test – and before departure home, you must have a negative Covid test. All reasonable and easy to comply with.
We touched down in Congo Town uneventfully but as we taxied to the terminal I spotted this plane. Looks to be a rough landing right there but one you can walk away from – the basic requirement in my book. So, no biggie.
After clearing customs and a half-hour taxi ride south on The King’s Highway from Congo Town we arrived at Mars Bay Bonefish Lodge run by Bill Howard.
The two stories house is being finished and the pink one is the kitchen and dining area plus three bedrooms. There is another guest house similar to this one on the premises. The accommodation was great. Rooms and beds were spotless and the food was excellent and interactions with staff were outstanding. Now, I must point out that it must be a challenge to run an operation like this where everything must be imported. However, the schedule ran without a hitch and there were no hiccups along the way. One day we got blown off the water by thunderstorms and wind but the weather is not under anyone’s control and we expected one storm day frankly.
The sunrise was spectacular from the porch while enjoying your morning coffee.
Breakfast was at 7 am and then guides picked us up at 7.30 am and we fished until 4 pm. This is hard work and lunch was packed and needed. After toiling on the flats an afternoon beer or wine is just what the doctor ordered and provided. Dinner is served at 7 pm and then you pretty much are out.
For me, the excitement is the speed of those fish. There are a lot of moving parts to bone-fishing which I have covered in a previous blog.
The single most important determinant of your success is your cast. You must be able to double haul and get the line out to more than 50-60’. Sure fish are caught closer to the boat but to be able to cast 40’ in a moving boat with the wind in your face requires that minimal skill set. You can buy a rod and a reel but you can’t buy a cast. Don’t go bonefishing until you have learned to cast properly is my advice.
All the anglers in our group caught fish and a lot of them – big and small. Simply put the fishing was outrageous.
Captain Baz with a big one (he always catches a big one but not necessarily the biggest one).
That distinction goes to Hutch. This one is estimated at 11 pounds.
I find the mangroves fascinating. The fish swim into those thickets on the high tide to forage. If you hook one and it decides to go there you are simply toasted. So, man up – max drag and apply maximal pressure. That can break off a fish, but you have a chance, but none if it gets in there. The big ones get big because they do just that. This was a recurrent scream “Fish on – oh f… heading for the mangroves!”…………
Then there is that – the fly line eating mangrove. It is a law of nature that a mangrove anywhere in the vicinity of your cast will catch your fly line. We were on a big flat with one tiny mangrove – point proven. Note the numbers on the gunwale. The number twelve is straight ahead and then – one – two – three on the starboard side. The guides give the caster instructions by saying “nine o’clock 60 feet” etc. Or “point one o’clock come right – see the fish?” and when you do spot the fish you cast. It does not work well for me to cast without having seen the fish. The guides are higher up on their poling platform and can spot the fish better (and they do this day in day out) and become so attuned that they can spot them one hundred or more feet out (sometimes even before they materialize).
But Greg redeemed himself repeatedly later that day.
A lone bonefish can be maddeningly difficult to spot but sometimes you find these big schools of fish and suddenly you can see them clearly. At the outset, I caught some fish from a school like that but after a while it got old. It is much more rewarding to me to find lone fish that are usually bigger but it is also a lot harder.
The flats we fished seemed to be endless and there were mangrove mazes you could pole into like this one. It took us two hours to thread ourselves through that particular maze.
It is a good strategy to be on the flats adjacent to the mangroves and especially if there is a bit deeper channel into the mangroves. The bonefish will usually return to and from the flat through these deeper channels. You need to be observant because we can be talking about very subtle depth differences. The bonefish in the video below was caught applying that strategy. You position yourself for an ambush and then you wait. The bonefish go into the mangroves on the high tide and must leave when the tide falls. I like better to catch a few big fish than a lot of small ones.
In the video Capt. Baz unhooks the fish without touching its body. The bonefish have this mucus around them that can be scraped off leaving them vulnerable to the sharks and there is a lot of sharks around. Notice that after the fish is freed it swims close to the boat for a while before departing.
On the flight home from Andros, the line “I would trade all of my tomorrows for a single yesterday” of bonefishing like that got some serious rumination. I decided against it – I will just go there again and again.
https://everyjonahhasawhale.com/wp-content/uploads/2021/11/6F7DC789-6228-4CEA-8F10-E20E37617FED_1_105_c.jpeg7681024Jonas Magnussonhttps://everyjonahhasawhale.com/wp-content/uploads/2019/03/FFI_9846_Logo®_Casting_Instructor_CMYK-600x476.jpgJonas Magnusson2021-11-30 12:00:182021-11-30 12:36:43Bonefishing from the Mars Bay Lodge – south Andros
Most lines are designed so, that when you add a correct leader and a fly, the outfit will turn over beautifully and we are happy. In other words, the fly lines are designed to turn over a certain mass i.e., the mass of the leader and the corresponding fly. As I have repeatedly mentioned in these technical blogs, a fly line without the leader will kick when cast. All fly lines are designed to have a leader added to the end of the fly line.
Design of fly lines
A fly line is designed to work with a certain mass that you add with your leader and your fly. If no mass is added to a fly line – it will kick when cast. Correct leader and fly (correct mass) added can be cast as intended. If we add a lot more mass for instance with a heavy fly the casting becomes problematic again. So, all lines have an optimal mass that needs to be added for that line to work well. Of course, this optimal mass is always caster dependent.
(In the two-handed world, the lines are designed the same way, but the exception is the Skagit line where you always must add a tip plus a leader for the system to work. That is outside the scope of this piece.)
Lots of tips available
All the line makers produce tips that you can add to a line if you wish to do so. There are a plethora of various density and length tips available. They are marketed as Vesileaders – Polyleaders – etc. An add-on tip is a tip made of PVC or polyurethane meant to be added to the end of a fly line. Those tips can either be tapering or level. However, the mass of the tip is usually not to be found on the packing.
Why use them?
You can of course add those tips to fly your lines. But what is the rationale for doing so?
You are fishing with a floater and your friend who is using a sink tip is catching them right and left but you are not. You can add an intermediate or a sink tip to your floating line to get the fly down.
However, adding tips to floating lines not designed to take that mass is just a quick, simple way to turn a floating line into a sinking tip line, but at a price. These tips will weigh several times more than a conventional leader (16lb leader I have weighs 11.2 grain). The weight of the tips is not disclosed but rest assured it is much more than the leaders. That mass of the tip will have to be added plus a little bit of tippet and the fly. They will cast terribly, predictably. When you look up these tips you will find marketing blurbs – “Casts well and turns your floating line into a sink tip” – those are written by some good casters, and they can undoubtedly deal with the extra mass, but average casters will suffer.
The mass again
Since the drawback to tips is their extra mass, the relationship of the added tip mass to the line’s head mass is the important one. Therefore, of course, adding a relatively light tip to a heavy line works much better than adding any tip to a light line.
Any line can be made to cast these tips if the angler shortens their fly lines front taper. Thus, more mass is at the tip and allows a line to cast a heavier tip. When the mass of the tip of the fly line matches the mass of the butt of the leader all is well. In many cases, though that will mean sacrificing the entire front taper, to get a reasonable match between the fly line’s end and the tip.
Generally, sinking lines are more difficult to cast than floating lines. That’s not a big surprise now when we know they must be heavy upfront to sink, and they can kick like a mule.
Why are the Sinking lines difficult to cast?
Remember they are not designed to be cast easily – they are designed to sink and cast big heavy flies – to catch fish floating lines can’t reach.
These lines kick because the leader can’t bleed away the surplus energy in the fly line’s end see this blog.
So, the real issue is the transition from the line tip to the leader. It is difficult to impossible to match the mass of the leader’s butt to the mass of the line tip. The line tip may be very small but quite heavy due to its density – remember it’s designed to sink. To match the masses the leader´s butt would have to be considerably thicker than the fly line’s end.
Correctly designed lines will have a mass profile that doesn’t change when going from the floating to the fast-sinking sections of a sink tip line. The floating part is huge, the sinking part is small, but the mass/inch is the same. Badly designed sinking tips lines will in addition have the clunky uneven mass transition.
Usually, fly slingers make two errors when they cast and rig sinking lines.
The line. The first error relates to the cast. Understandably, casters try to cast the sinking line as they would cast a floating line, and that does not work very well. Cast a line like that straight back it will stop and bounce and create slack. Because of the kick, with each cast, control of the line is lost, and it compounds (remedy below). Remember the big and heavy fly usually used in tandem with a sinker is waiting for its opportunity to strike the back of the caster’s skull – ears are a good target too. So, false casting should be minimized and can be downright dangerous.
The leader. The second error relates to the leader. The butt of the leader anglers use is frequently way too thin, so the transfer of energy will not be optimal creating more bounce. To use a suboptimal leader is an unforced error. Sometimes your casting abilities are evolving but the effort of tying on a suboptimal leader is the same as tying on an optimal one. So, pay attention to your damn leader’s butt.
Since the issue with sinking lines is at the transition to the leaders only, there isn’t a need for long leaders, at least not to cure casting ills. The leaders need to be long enough to temper the kick somewhat, but no longer. When the line kicks so does the leader, of course. The part of the leader’s butt forward from the fly line, helps to temper that kick, usually 2-3 ft. of butt is enough. There are diminishing returns going longer than that. Then add a taper and tippet and a total leader length of 4-6 ft. works well for casting, and the short leader also gets the fly down quicker than a longer leader would do.
The solution. Forget nice sharp loops these lines can’t be controlled casting that way. Open your loop to minimize the kick. Make one back cast and then briefly lay the line down in front of you. Pick that line up and make another back cast, shooting line to get the line’s head out of the tip-top, then shoot the front cast. No false casting is required. Lay down every fore-cast once the head is out of the tip-top and shoot the next fore-cast. This is much safer and easier to do than trying to false cast a with a dense head and a big heavy fly. A Belgian or an oval cast works very well, especially with an on-shoulder wind. As you retrieve your line and get ready for the next cast, the line is now in the water, not on the water as the floater is. It is not possible to go into a backcast with the line sunken like that. You might even break your rod if you tried. The solution is to make a roll cast or two and get the line to the surface. Once there we can make our usual pick-up. Remember to pinch down the barb for your own sake if not for the fish’s, just in case.
Line management of a sinker. Fishing in water the stripped sinking line will sink if not managed. Obviously, the line does not come as easily from the water as a floating line comes off the water. The stripped line can be coiled and held in the stripping hand, or a stripping basket can be used.
Rod. Casting sinking lines isn’t about short distance and accuracy, it’s all about distance and covering a lot of water. Therefore, soft rods (noodles) aren’t appropriate. In the right hands they can work, of course, but why fight a slow rod when a faster one would work better? Beginners and intermediate casters would be well advised to use fast rods for casting sinkers.
This picture has nothing to do with sinkers but just begged to be posted.
All fly casters have experienced a fly line “kick.” So, what is this kick? The fly line kicks when the tip part suddenly accelerates at the end of a cast and careens about (like a whip does). The reason behind the kick is that there is undissipated energy left in the loop when it straightens. That energy must go somewhere and the end of the fly line kicks thus dissipating energy. When casting floating lines, the kick is mostly a casting error (too much power), but it can also be used to the caster’s advantage (more later). Lines, where the mass of its head is pushed forward, are prone to kicking whether it is a sinking tip or a floating tip. The mass upfront is the issue, not the line’s density per se. When casting a line with a heavy sinking tip it will kick to a varying degree. Let’s break it down into various components.
Any line, cast without a leader, will kick no matter how gentle the cast. Just go ahead and try for yourself. There should be, by necessity, a little bit of energy left in the fly line to turn over the leader and the fly. (Now it is also obvious why you need more force to turn over a fly as it gets heavier). The leader is designed to dissipate the rest of the energy and still have enough to turn over the fly. Now you immediately realize that the leader must be constructed in such a way as to be able to do this. Imagine a scenario where you put a 6X 3.7lbs tippet on a 15# flyline (Diameter 0.005’’, 0.13mm). You intuitively realize that’s never going to work. Mass moves mass is the mantra (see blogs below). And the reason is that the mass of the leader’s butt is just too small to accept the excess energy. The mass of the leader’s butt is predicated by the diameter of the butt (not the break strength).
When I cast a floating line, I like to spend just enough energy to turn the ensemble over and lay it out straight in front of me. However, I can make any line kick by just using more force. Now, this is a casting flaw unless you want the line to curve at the cast’s end. There are two named casts where we use excessive force to curve the line. First, we have the Tuck cast where we cast in the vertical plane and overpower the cast, and the line and leader tuck down, and we can make the fly land first on the surface. This is used for instance when you want the fly to sink fast as in nymphing.
The other is the Curve cast where we cast in the horizontal plane and curve the line around an obstacle for instance a stone in the water. This is possible to do when casting in the horizontal plane. The trick is to overpower the cast and the line curves either to the right with a horizontal left-sided cast or left using a horizontal right-sided cast.
It is the same principle and the same cast. The tuck cast is in the vertical plane and the curve cast is in the horizontal plane.
The line’s design
Now undissipated energy can be there because of the line’s construction. All lines where the mass is pushed forward will certainly kick more than most other line designs. Sinking tips will kick more because of their mass (not density), but floating lines like the one above will also kick. But that’s OK, these lines are designed to cast bigger flies AND for the sinkers, the tip must sink fast so there is lots of mass in the front. But we don’t care, we’re not throwing dry flies. Good for big/heavy flies. If the tip casts smoothly it does not sink well and thus fishes badly. If the tip sinks well and fishes well it is harder to cast. You must pick your poison!
Sinking lines and sink tips are made by incorporating small pieces of tungsten (from Swedish – literally heavy stone) into the PVC coating. This increases the density of that part of the line. The tips are furthermore thinner than the floating head part and that fact is responsible for the decreased drag and the speed-up of a line thus constructed.
The line kick can be much more subtle. One of my friends when rigging a new 2-3 wt. line cuts off the factory welded loop and attaches the leader with a 2-turn needle knot. He feels the welded loop “kick” just a bit and doesn’t like that. Line/leader attachments often result in a little lump of mass right where we don’t want it. But with the right leader butt and attachment method, the transition from line to leader can be made very smooth.
In my professional life good instructional videos were priceless to me. However, I did not get much help from the videos before I had mastered the basics, and only then did I understand what was going on, and they became extremely valuable. So, I think complex motion is very hard to teach to beginners unless some basics are mastered first.
We all have seen on some thread or the other that some beginner queries. “How can I learn to fly cast?” The answers come thick and fast. “The xxx Fly shop has some awesome videos, and you will learn it in no time.” Or “Cedric at the Churchmouse will take you out into the street and sort you out in no time.” The sobering fact is still that most fly casters could improve a lot.
A quick Google search “fly casting videos” yielded “about 40,400,000 results (0.55 seconds).” I haven’t watched all of them and I won’t. But I have watched a lot of them, probably way too many. The mere fact that there are so many leads me to conclude that most of them are bad. Why would we keep producing millions of these videos if there were some good ones out there to do the job? Whoa – I hear you scream – “are you saying that all instructional videos are useless?” No, I am not saying that. I am only saying they are useless for beginning fly casters, who don’t have the basics down pat first. The speed at which everything moves during fly casting makes it very hard for a beginner to get what’s going on. For instance, in a slow cast, the rod tip can be traveling at 60’/sec (40 miles/hour). If a beginner watches a beautiful fly cast for the first time, he/she only pays attention to the loop, and “oh how pretty it is” is a common exclamation. Because of the speed at which it happens, it is hard to understand all the various steps that are needed to produce the pretty loop.
If the instructional videos worked for beginners, we should all be casting, and golfing, and …… (insert any sport you like) – like gods. However, sadly we don’t. I think the reason the videos don’t work for beginners is that they don’t understand what they are watching. In many videos, the teacher casts nicely but the verbal part doesn’t match the casting action leading to a Gordian knot of misunderstanding. There are standardized casting terms adopted by FFI
and it would be great if they were used correctly by everyone in the casting community especially those who are producing the teaching videos. Unfortunately, these simple terms are not used by all teachers.
I concede that a few of the videos are pretty good and some are excellent, but most are lacking. So, what are the odds of a beginner locating the useful ones in a pool of forty million videos! The odds are bad. So, the odds are, that the poor student is watching one of the majority of videos that are substandard, thus learning the wrong stuff! Even the videos with good content are usually bad because the “celebrity” presenter bloviates and hides the good stuff in a bunch of fluff words. There seems to be an inverse relationship between the quality of the video and its length. The same goes for the number of words used.
The videos I have found to be good to great are found on FFI’s website.
I have learned a lot from Paul’s videos but only after I got the basics in place. I am not saying that these two sites are the only good ones. However, they are the best I have come across for beginners.
Even the good ones aren’t all that helpful, mostly because they can offer no feedback to the unfortunate beginning learner. The learner watches the video then goes out to try out what she’s/he’s “learned”. The student thinks she’s/he’s doing what has been learnt but isn’t and doesn’t know it, so ends up no better and more frustrated.
So, what can be done? The obvious step is to turn the process on its head i.e., film the beginners and then have the instructors point out all the things that need to be addressed.
The very best way to learn the basics is to get solid instructions from some certified casting instructor. However, anglers will rather spend their money on gear they don’t know how to use properly. One of my blogs delves into the GAS syndrome (gear acquisition syndrome),
From the floating line, we can graduate to sinking lines. The advantage of fishing a sinking line is obvious. A sinking line differs from a floating line in two important aspects. The line’s submerged part can’t be mended. The sunken line can’t be recast until it has been stripped or roll cast to the surface. The line needs to be brought to the surface for a pickup. Either the line must be stripped to the leader and/or roll cast and thus get it to the surface (digging the line up to the surface – we call it). For that reason, full sinking lines are not very practical in rivers as there is no mending and lend themselves better to lake fishing and saltwater fishing.
The sinking lines are called full sinking if all parts of the line are denser than water. The lines that have a sinking part and a floating part are called sink-tip/head (depending on the sink length) lines.
A. Full Sinking Lines
The full – refers to the fact that these lines have higher density throughout their length than water. They simply sink because they are denser than water, if and when they break the surface tension. That does not mean that the density will be the same throughout. Remember, the running line for instance is much thinner. The multifilament woven core contributes more to the overall density of that part of the line (practical density less), as compared to the head part (practical density more). This fact will affect how they sink and – fish. Badly constructed sinking lines can be unpleasant to cast but can sink and fish very well. Their construction revolves around how they cast and how they sink. The current sinking lines can be nice to cast if the density differences of the various portions are minimal, therefore they don’t noticeably kick.
I.P.S. this or that? There is no industry standardization behind the inches per second numbers. Each manufacturer has its own way. But generally, the inches per second (I.P.S.) we see printed on the fly line boxes is found by placing a piece of the fly line in a water column, and then the sink rate is just measured. The sink number given will be representative of the densest part of that fly line. I stress that this is measured in still water. Whether that line will sink like that, in the fast or slow water of a river, is another question entirely. You can safely rely on that the line will not sink as fast and not as deep in moving water.
Lines 1, 2, and 3 are co-called standard lines.
1. Intermediate lines
They sink, albeit very slowly, and therefore belong to the sinking line class. Why they are called intermediate – instead of slow sinking lines, I don’t know. Who says it must be logical? The density differences throughout the line’s length are modest; therefore, they don’t noticeably kick when they are cast. They are generally pleasant to cast and behave similarly to a floating line.
The slowest sinking lines are called intermediate and are supposed to sink 1-2 I.P.S. (inches per second). They sink slowly but sink very slowly if at all when stripped in. They are great when the angler chooses to fish just under the surface. The intermediate line can be used just about anywhere. I use intermediate lines in the salt, rivers, and lakes. The only drawback to their use is if/when the running line sinks making it a tedious process to “dig” up the line and recast. The coating of the whole line is of the same density. The running line is so thin that the density when we account for the core is less than the head’s density. Thence the running line will not sink much.
2. Medium sinking
These lines will sink 3-5 inches per second.
3. Fast sinking
These lines will sink 5-7 inches per second
Medium and fast sinking lines are built like the picture below indicates. The line’s density and therefore its sink rate varies between different lines. However, the coating is the same along the line’s whole length. The resultant functional density along that line will NOT be the same though because of the varying thickness of the coating and the contribution of the level core.
Because of the variable density along the line’s length, the belly of the line will sink fastest (it is the densest). The tip of the line is thinner (less dense), and it will sink slower. The RL will sink slower than the belly and the tip too. Therefore, the line will be in a U shape and strike detection becomes difficult because of the slack. Fishing a sunk line is all feel, and it is a serious handicap that the line isn’t straight. That takes us to the next type of line, and if you took your minerals and vitamins this morning you have already figured this one out.
4. Density compensated sinking lines
Above we have two different lines in this class. We can place the densest coating in the head of the line, and then a bit less dense coating in the handling part, and finally the least dense coating in the running line. When that’s done, we have three different densities along the line. Now, this type of line will sink straighter and does not become U shaped in the water (no slack). This will increase our hookups because of the elimination of slack and much better detection of strikes.
B. Sinking tip/head lines
The sinking lines above have one cherished quality namely they get the fly down, but mending is not possible, and you must spend time “digging them up.” So, it is logical to make lines that both sink and float. Mixing the sinking tip with a floating part. Now we have a line that sinks in front but can be mended and roll cast with relative ease.
1. Sink tip
The length of the sinking part can be varied and so can the density of the coating. These lines excel in river fishing. The fly is in the water column where the fishes are. You retain the ability to mend and control the line with the floating portion. A couple of strips will bring the sunken portion of the line to the surface from which they can be roll cast with ease. Your choice of density for the sinking tip depends on the size and flow rate of the river to be fished. Short slow sinking portion for a small river and a longer faster sinking tip/head for a big fast river. The length of the tip can be anywhere from very short say three feet to include the whole head.
This line has fifteen feet of a clear intermediate section (Belly 1), but the rest of the line is floating. Now, just the 15′ distal feet will sink, and the rest floats so it is very easy to recast. No roll casts are needed to bring the line to the surface. It’s already there. An additional advantage is the ability to mend if there is sufficient mass in the tiptop (see a previous blog). This line above is not great to roll cast because of its short head, but you get the picture. Of course, the terminal intermediate part can be longer or shorter there are many options to choose from.
This one is available in three density iterations, intermediate – sink 3 – and sink 6. The Sink tip is between 8-16 feet, depending on the line’s weight. This line’s head is longer making it easier to mend.
2. Sink head
This type of line has a head that sinks. It can do so slowly (Sonar Sink 30 Clear) to fast (Sonar Surf) it all depends on the intended use of the line.
This line has a clear 30′ head that is intermediate or slow sinking. The rest of the line is floating. There are two advantages to that. First, you can easily mend the handling part of the line, and second, you don’t need to dig the line up to the surface before recasting.
This line has a sink 6 (6 ips).
Casting sinking lines
Generally, sinking lines are more difficult to cast than floating lines. That’s not a big surprise now when we know how the lines are constructed with different densities along their length. They are heavy up front and can kick like a mule (….and bite like a crocodile J. Cash).
Usually beginning casters make two errors when they cast sinking lines. One error relates to the cast. Understandably, they try to cast the sinking line as they would cast a floating line, and that does not work very well. The other error relates to the leader. The butt of the leader anglers use is very often way too thin, so the transfer of energy will not be optimal. https://everyjonahhasawhale.com/blog/your-butt-is-too-small/
Am I serious? Now doing a piece on the running line – really? You might think that the running line is the simplest part of the line system and it might be. That there is nothing worthy there of any thought or writing. You would be wrong. Let’s dive into it.
What is the running line?
The Running line (RL); extends from the line’s end to the beginning of the rear taper (RT) into which it seamlessly blends. Below is the Amplitude Anadro with its forty feet of RL.
Why do we need any running line at all?
The mass of the Anadro is mainly in the head of the line. That’s the part we bend the rod with and subsequently, as we release the head it pulls the RL out. Let’s cast with and without an RL and examine the consequences. We cut the RL off and tie the backing straight to the Anadro’s head. The head will shoot out just fine, but it will become very unpleasant to strip the line back with the backing. For this, to work, we need to have some backing off the reel. Nothing tangles as bad as thin backing and we will run into that problem with the loose backing. This line lends itself well to very long casts, far longer than the head’s length (60’). Therefore, it is much better to have those 40’ in the form of the running line. Better for handling and it does not tangle as grievously as the backing. The running line is thin, self-lubricating, and textured (see the previous blog) and has a low coefficient of friction.
Even with casts up to 100’ we have good control over the cast and gain control over mends as soon as we have stripped to the RT. By choosing a line with a long rear taper we can compromise, and still have enough mass in the rod tip to have very good control over our line for our mending. And we still have excellent casting control over the line.
Let’s look at another line, the MPX. The MPX’s head is only 36’ (6# line). You can get this line out faster since the head is considerably shorter than the Anadro’s. It will turn over well because its mass is pushed forward in the head. The FT (front taper) is now 5’ and you can still turn over a fly gently. If you cast it far you will much prefer stripping in the RL instead of messing with the backing. The head is 36’ plus for instance a 9’ leader, and you should be able to comfortably roll cast all those combined 45’. Most casters can’t roll cast more than 50’ and seldom need more. The Anadro can be roll cast further because its head is 60’. The reason behind this is down to mass again. The running line is simply too light to move the much heavier heads.
Do you believe me now? We do need a running line. A very thin one will cast the longest but is prone to tangles. Too thin a running line is just plain unpleasant to touch, and is difficult to handle, and is nothing but trouble. The thin line has less friction but tends to tangle but by making it stiff we can counter that to a degree.
Stiff lines are coily but we can pull the coils out by stretching the lines, but we always seem to forget to do that. The RL tangles less if it is slick. The slicker the better. Both these lines are self-lubricating and textured but by applying silicone or such they can be made slicker decreasing their tendency to tangle.
A very thick RL is heavier and has more friction. So, the solution is the compromise in the construction of the rear taper. We don’t have much choice in the diameters of the running lines we buy, but that’s fine, the manufacturers have honed it to the best compromise size for that line weight.
Imagine that you are swinging a fly with each of these lines, and you have 55’ out, and you need to mend the line. In the Anadro case, it is easily accomplished because there is enough mass in the tiptop to move the rest. However, in the MPX case, you will find that much harder as you only have the thin RL in the tiptop and not enough mass to move the rest of the fly line.
Casting with overhang (length of RL outside the tiptop) is not easy for most casters. Just by glancing at the picture of the lines above it is clear that the Anadro lends itself to longer casts. When carrying 70’ of the line the overhang is 10’ but is 38’ with the MPX. So, the ratio of the RL to head length is a really important parameter. Those who can cast with overhang do it by keeping the running line and the head straight. If that’s accomplished a thin light line can power a thick heavier one. However, when the RL isn’t straight the cast fails.
The variables of the running line
The diameter is important. Thin lines shoot much better than thick ones. They are lighter and have much less friction. But a light coily running line can pose several problems. It gets blown around especially in a boat and that leads to tangles. Coily lines manage to tangle all the time. Of course, by stretching the line the coils can be pulled out, but anglers are mostly a lazy bunch. Thicker running line affords better control of the cast and the mending. However, you can’t cast as far because of their weight and friction.
The mass is important. Small diameter leads to a light running line (see above). Additionally, a light running line in the tiptop can’t control the rest of the line. The mass is simply too little. By increasing the diameter of the running line we are also increasing its mass. That gives us more control over our casting and line mending. But it also leads to shorter casts (see above). If the line was a conventional full sinking line the RL would be made of the same high-density material as the head. Might be small but would still be heavy, but he mending considerations don’t apply to the sinking lines.
The stiffness. Thin stiff running lines shoot exceptionally well. But a thin running line tangles so easily, but being stiff is a sort of an antidote if the line is stretched straight.
The COF (coefficient of friction/slickness). We all know that the hyper slick thin, light, running line is going to cast farthest of these combinations. All other parameters the same – the slicker running line is going to shoot the best. We even have textured self-lubricating shooting lines now.
The density. Mostly the running lines are floating parts connecting to a whole head, that can be floating, intermediate, or with varying sink rates. The RL and the head of the line (RT + belly + front taper (FT)) come in one piece, sometimes called an integrated line. Thus the “running line” is an integral part of a WF line. Most integrated lines (which are WFs) have a small diameter, light RLs but very heavy heads.
Mostly the RLs will have the same density along its lengths. There are conventional full sinking lines made with the same material its whole length.
However, there are modern lines where the RL comes in three densities. The Sonar Titan (Hover / sink 2 / sink 4) has a hovering RL for approximately 45’ and then there is an approximately 20’ part with sink 2. The head is finally rated sink 4. (Sink 2 simply means that it sinks approximately 2 inches per second (ips), etc.)
Then there is the Sonar Titan (Sink 3 / sink 5 / sink 7). This one has a sink 3 RL for approximately 45’ and then there is an approximately 20’ part with sink 5. The line terminates in the head with a sink 7.
So, we can have lines where the RL’s density is the same throughout, but these two examples are sporting two different densities in their RLs. These lines go by the moniker – density compensated lines.
I hope that you now agree with me that the running line is a very important part of the fly line. I would certainly sorely miss my running line if it were not there, next time I go fishing. And now you too, have an inkling how it works.
“What fly line do I need?” – is a much better question.
This a recurrent question we all get personally, or it appears on some chat site. There is really no correct answer to this question. However, the chat sites immediately fill with – “I just got line x, and it is wonderful, can’t go wrong with that.” And more in that vein, lots more. The answers and advice are all given in the spirit of generosity and are undoubtedly well-meant. But this question can’t/shouldn’t be answered, until you have an idea about the intended use of said fly line.
Choose a line for the fish species?
Ok, so now you think the choice of line revolves around the fish pursued. That would be wrong, too.
The mass of the fly to use dictates the line choice!
There it is – once again and we come back to mass. But think about it a bit. How can it be any otherwise? Mass moves mass, and therefore the line’s mass must match the flies mass. The correct way to go about this, is to visualize the flies to be cast. Not their colors or shape, but their mass (and drag, too).
Let’s assume that the prospective buyer is a novice to trout fishing, and she/he loves casting weighted Wooly Buggers and Streamers. However, on the advice of well meaning anglers (or pranksters) an Amplitude Trout is purchased. The reason I use SA’s lines is that they are the industry’s leaders, and their lines are the best I can get for my needs.
This line is absolutely fantastic, but not for Streamers. Why not? The forward taper is 12-foot long, and hence there isn’t enough power in that head to turn over a heavy Streamer. So, now we have recommended a fantastic line for smaller flies, but the angler wants to cast big and heavy. That’s not a good situation to be in if the advice is heeded. Pay attention the the Trout’s long rear taper. This line can easily be cast far. So, what is a good line for an angler casting streamers. My advice would be the Amplitude Anadro line.
The Anadro has a short front taper (2-3′), and that means it will turn over hard, and it has the power to carry a heavy Streamer. On top of that, the Anadro is 1.5 sizes overweighted, meaning that a #7 Anadro weighs between a #8 and a #9 line. That will ensure plenty of power to turn over heavy flies. The Anadro excels at long distance casting and that is evident by looking at the long back taper. The reason that lines are not true to their line designation is that rods have become so stiff that only elite casters can bend/load them with the designated line. Intermediate casters must have more mass (line size up) to bend the rod. The line makers know this and have responded accordingly.
The second question I ask is how far can you cast or how far do you need to cast? Let’s now imagine that our angler is casting light flies in a small stream. The Amplitude Trout would easily work for that job. Of course, there are other lines that could work, too. For instance, Amplitude MPX or Amplitude Double Taper. What about light flies in a big river? The Amplitude Trout would be perfect in that situation because of the long back taper making long casts a breeze. Heavy Streamers on heavy lines banged down are probably not a good idea in a small stream. But they are absolutely an excellent idea in big rivers. Pay attention to the Anadro’s long rear taper of 30′. To be able to make long casts, this is the best taper configuration to accomplish that.
Bonefish are notoriously wary customers. Something big and heavy landing on top of them guarantees that they bolt, and fast. So, we use a line that we can lay down gently. Because of the usual wind on the salt flats we need rods #7-9 to be in the game. The flies we use could easily be cast with something smaller, for instance #4, but the wind would kill us. This is a good example of the necessity of using tackle to cast a light fly. This is frequently done too, when casting small flies to big salmon. When I have gone fishing for bonefish, I make a beeline for my Amplitude Bonefish lines.
Generally, when fishing in the salt you are use something big and heavy. Therefore, you need a line with some serious punch. Or in other words, a line with a very short front taper. The Amplitude Infinity Saltwater is a good all round choice.
If you still need more power to turn over some monstrous fly, there is the Amplitude Tropical Titan. Here, a lot of the head’s mass is pushed forward, and this baby will turn over hard.
First choose the fly – then the line
Now, the process of choosing the tackle is obviously going to start with the fly. First you must have an idea of the weight/mass of your intended flies to be cast. Ok, so now when we have that clear, we can choose the line that has the physical parameters to be able to cast the chosen flies. Remember, heavy lines can cast both light and heavy flies, whereas light lines can cast light flies, but struggle or can’t deliver heavy ones. There are only two parameters of the fly that influence its castability. Firstly, there is its mass, and secondly, the air resistance or drag.
Now lastly the rod is chosen
Now when you have chosen the line size that can handle the job, it is easy to pick a rod that can handle that line. Now remember the marketing in our sport is pervasive. Anglers have been led to believe that they need a trout rod, then a salmon rod, and my God don’t forget the saltwater rod. This is utter nonsense. The rod is a piece of graphite, handle and rod guides. It bends, then straightens and can easily break. It is dumb as a brick and an inanimate object. I use my #8 NRX Loomis to cast certain weight flies, and I happily use that rod for all fish likely to take those flies. A heavy line and heavy rod, can deal with a heavy fly, and also a light fly. The converse does not work. So, don’t show up under gunned.
It is important to know that there is no objective parameter to adhere to when a rod is made. After a rod is made, it is cast by some expert with various line weights, and then the expert decrees, “this is henceforth a #7 rod.” I repeat, no standardized objective measure decides the rod ratings. This newly minted #7 rod obviously casts best with a seven line, if you are the expert. It might work best for you with an “8 line, and some would like better to cast it with a #6 line. All fly rods can cast several line ratings, there is nothing mysterious about that, and it is perfectly fine to use the line weight you like. So, all this writing about the crime of underlining or over-lining is a bit misleading. It is your rod and your line, and just use it as you like best. You have my blessing.
https://everyjonahhasawhale.com/wp-content/uploads/2020/08/Screen-Shot-2020-08-02-at-19.03.37.png9621919Jonas Magnussonhttps://everyjonahhasawhale.com/wp-content/uploads/2019/03/FFI_9846_Logo®_Casting_Instructor_CMYK-600x476.jpgJonas Magnusson2020-08-27 12:56:362020-08-27 12:56:37How to choose a fly line!
The running line is called celestial blue. The belly part is bamboo colored, and finally the front taper is blue heron. My eyes say grey, but I can go with blue heron too, because it is grey. Initially, I did not like these Harlequin lines, but now I love them. I find it advantageous to know how much line I am carrying, and with the coloring scheme, it is so easy. These colors also help, when I am teaching casters. Many of them tend to slip out line as they are false casting, and thus exceed their carry limit (all casters have a limit as to how much they can carry of line (keep in the air)). Most intermediate casters can carry 40′, and I use the end of the belly to remind them of the position. Casting with too much overhang (running line outside the tip top) is hard for beginners, but if they practice, they can carry more and more line, because they can keep the backcast straight. The front taper or grey part is about 12′ and the leader is 9′. Being cognizant of these lengths helps to pinpoint where the tackle is.
The core is braided multifilament nylon. The filaments are solid Nylon, but braided together to make strands (16 strands). The way they are braided yields a hollow braid. Each strand of yarn has a small amount of air trapped in it when coated, but most of the air in the core is in the hollow center, see previous blog. The line is not painted after being made. The PVC used to coat the core has a blue – then bamboo colored – then grey pigment, and the micro-balloons, added into the PVC coating mix. This coating transitions from one color into the other seamlessly. How that is done, I haven’t a clue, so we all can be glad that I am not the one doing that. The SG of the PVC coating of the level tip is nowadays 0.85. On top of all that the gray part has more air trapped in the mix (see later).
The line has seven red boxes with some hieroglyphs on the website. I will decipher them as we go. On the website there is some text under each box, but much too small for reading. Probably put there by the elves making these lines.
Two types of texture
1. The Shooting Texture
After the coating is applied it is time to texture/emboss the line. The running line is textured/embossed with what SA calls, “Shooting Texture.” Textured lines have less contact with the rod guides, so they shoot better for more distance when needed. The texturing also increases the surface area of the line for better floatability. This texture is not rough on the fingers, but the rear taper is not textured to give a tactile reference point (see later). Then the Belly of the line is textured with the same “Shooting Texture” to the front taper. Shooting texture helps, you guessed it, in shooting the line, and it increases the floatability a little bit, too.
2. The Floating Texture
After the coating is applied it is time to texture/emboss the line. The front taper and the level terminal tip are textured with the so-called “Floating Texture,” and that is an ingenious engineering application of the so-called “Lotus effect.” – https://en.wikipedia.org/wiki/Lotus_effect – Now, an engineer at SA applied this knowledge to the surface of a fly line called Sharkskin in 2007. The natural hydrophobicity of PVC was kicked up several notches, and the line floated higher. Although the Sharkskin line shot great and floated high, the surface is rough on the fingers, so now the texture is limited to the front taper, and terminal level tip, and it increases that part’s floatation. This part of the line is not handled much.
I will repeat this. The line is textured/embossed with two different types of etchings. Seriously, this a job for dwarves. “Floating texture” helps, you guessed it, in floating the line, but its cast-ability is immaterial as this part is almost always outside the tip-top.
Improved dry tip
The crucial part of any floating line is the floatability of the tip. By increasing the amount of trapped air in the tip section (the gray part), the SG can be brought down to 0.80. This will float the tip higher. The tip floats because of manipulations of the SG, and by manipulating the surface into becoming hyper-hydrophobic. This is really hard core engineering.
The AST (Advanced Shooting Technology), was introduced 1998, and now all quality lines have this feature. A SA engineer came up with this incredible idea, in principe, a self lubricating fly line. AST means that silicone is incorporated into the coating mix. Then as time goes by, it leaches out onto the line’s surface. Such a line is much slicker than a line without this feature, and casts much better since the friction in the rod guides is diminished. AST then became AST+ after some chemical sorcery – making the line slicker.
On the front taper the line ID is printed. I really like this feature, but with time the print wears off my lines. Therefore, I mark the weight of all my lines at the end of the running lines. A long black dash – 1” mark means five. A half inch dash means one. I read from left to right — —– becomes 4, —– — becomes 6, —– —– is ten (like the Roman system). This is quickly done and does not wear off. This is a really helpful little trick when you have many lines.
I really like welded back loops on all my fly lines. These back loops easily last the lifetime of the line. I like front welded loops on lines from #5 and bigger. On the smaller lines the loop is just clumsy. The fly line loop adds more floatation, but the butt loop connection adds more nylon (SG 1.2), making it an even game, so the flotation is not an issue. However, the front loop is somewhat ephemeral, and will fall apart some day. There is no getting around this one – you need a strategy to connect your leader to the line, without the easy fix of looping them together.
Tactile reference point
Part of the rear taper of the line is smooth, i.e. there is no shooting texture, and you can feel that. It supposedly helps to identify how much of the line is out. But that does not excite me since the colors are already there. When I used this line in Iceland last fall is was so bloody cold that I could just about feel the line, the tactile reference point was not felt.
Cost and quality
Fly anglers can become very excited, bordering on agitated, about their fly rods, and then have no clue about their fly lines. As I gain experience teaching casting, I am now in the camp that maintains that the fly line is the most important part of a fly angler’s setup. I like everything about this fly line. For dry fly trout angling it is fantastic. For salmon, when you are using small flies, it is superb. Furthermore, it is true to the AFTMA weight standards, i.e. a seven-weight line is exactly 185 grains. The front taper is twelve-foot long, so if I were to use very heavy flies, I would switch to the Anadro line, with its much shorter and powerful front taper. When you go through the points above, you realize that there is some serious engineering behind this line. SA maintains that this line is very durable (at the very least double lifetime or much more), and will last without loosing its characteristics. I have not owned one long enough to know that. However, the quality of this line is second to none.
I do not much like lines that are made stiff, hence coliy, or the so called tropical lines. It is just my peccadillo and I am the one living in this body. I left the Amplitude Trout and Anadro lines out in the heat (90 F) here in the Florida Panhandle. After that they were a tad limp, but when I still could cast the whole line, I can see no reason to have tropical lines in my arsenal anymore. Saves a bundle right there.
This line retails for $129.95. Is that prohibitively expensive? That is up to debate, and each of us might reach different conclusions. If the line lasts as claimed, its price is suddenly very attractive, for instance. Whatever your take is on the price, there is no better line in its class.
https://everyjonahhasawhale.com/wp-content/uploads/2020/07/DSCF9581-1.jpeg535802Jonas Magnussonhttps://everyjonahhasawhale.com/wp-content/uploads/2019/03/FFI_9846_Logo®_Casting_Instructor_CMYK-600x476.jpgJonas Magnusson2020-08-13 18:49:162020-08-15 08:26:39Fly line constructed by engineers - built by dwarves!
A floating fly line is made of a braided nylon core, onto which PVC is added as a coating. The specific gravity (SG) of nylon is 1.2 and the SG of PVC is 1.4. With those numbers the line should sink. So, why does it float? (For perspective; Aluminum has SG of 2.7 and marble for instance has SG of 2.6)
Specific Gravity / Relative Density
SG over 1 – denser than water (sinks), conversely SG less than 1 – less dense than water (floats). Here is a simple review –
When you are dry fly fishing you need a fly line that floats. Now that was an intelligent sentence. We like to turn over the leader gently, and that means a thin tip. If the line tip sinks, it will pull the leader butt under. Conversely, if the leader butt pulls the line tip under, it sinks. The line’s tip SG is ~ .85 (see later), it wants to float and will, unless something makes it sink. The leader has a SG of 1.2, and once under water, the whole leader system will drown, taking the fly under. The critical (to floating) part of the fly line is the level terminal tip. It is easy to make sure that the thick belly of the line will float like a cork. However, the fly line tapers and ends in 6” of level tip. Now the diameter of the tip is 0.037” and the relative contribution of the coating is much smaller than in the belly part.
The Core and the PVC
The core is braided multifilament nylon. In between the filaments, which are braided into hollow strands, there will be some air, and the coating traps some air around the braid in the manufacturing process, which is the big contributor of air, bringing the SG of that part to just under 1.0, but not much. In 1954 SA added air bubbles to the PVC coating, and lo and behold — the new line floated. This is considered to be the first modern fly line. Subsequently in 1959, SA introduced micro-balloons into the PVC coating. The SG of the PVC coating of the level tip is nowadays 0.85. So, that takes care of the SG problem.
Any body placed in water will displace a certain volume (remember Archimedes?). Archimedes’ principle
states that the upward buoyant force, exerted on a body immersed in a fluid, is equal to the weight of the fluid that the body displaces. So, now the line weight is less than the weight of fluid displaced, and the line floats. The SG is a reflection of Archimedes’ principle in relation to water’s SG set as one.
Surface tension (https://en.wikipedia.org/wiki/Surface_tension) is the tendency of liquid surfaces to shrink into the least surface area possible. We all have been shown iron needles floating in water, because of the surface tension.
Water’s surface tension is high. The PVC on the other hand is hydrophobic. By certain chemical additions (don’t know which – probably secret) to the lines’ surface, the hydrophobicity of the PVC can be increased. The silicone that leaches out of the line increases the hydrophobicity of the line, increasing the floatation, too. We can also apply silicone to our lines with good effect. We all know that cleaning our lines makes them shoot better and float better. A dirty line is just less hydrophobic – so now go clean your lines and buff them with silicone.
We know that a small piece with a bigger surface area will float better, because of the surface tension. The line’s surface area can in fact be increased by texturing. This is very similar to the dimples on golf balls. So, the surface area in contact with water is increased, and the textured line will now float higher.
The “Lotus effect”
https://en.wikipedia.org/wiki/Lotus_effect – Scientist have noticed raindrops falling on lotus leaves, and then just roll off. It turns out that the surface of lotus leaves are hyper-hydrophobic. The reason is that on the surface of the lotus leaves there are microscopic pointy structures, replicated millions of times. Engineers can mimic that effect by manufacturing lines with a rough surface (Sharkskin was the first in 2007). This surface is rough on the fingers. However, the hydrophobicity of the line can definitely be effected by manipulating the line’s surface.
Simply put, floating lines are lighter than water, and are hydrophobic, so they sit higher on the surface than they would if hydrophilic. Lines can be made hydrophobic chemically and/or mechanically.
Saltwater has a specific gravity of 1,024, so it is denser than freshwater. This allows us to construct a floating fly line for the salt, which can have denser coatings (thus thinner). SW lines’ slightly denser coatings make them tougher (PVC is weakened by most additives), and a bit thinner, which improves casting, i.e. less wind resistance.
To wrap it up
Shape of line and leader
Before we leave the floating line we need to look at shape. I have owned lines (and you, too) that look like a “slinky” when they come off the reel. It is a floater all right, but in this configuration it will sink. The part of the line that is above the water will push the bottom of the coils under. Once a line is subsurface it no longer has the benefit of flotation by being hydrophobic, now it is repelling water in all directions, not just from the bottom.
So, STRETCH your fly lines before you start using them. The same must obviously apply to your leader, so stretch that too while you are at it.
The line leader connection
If the water surface is calm, it is easy to get leaders to float, but we rarely have that luxury. Chop/turbulence causes parts of the leader to sink, and it is not coming back up due to its SG (1.2). It’s easy to float a 6X tippet leader (0.005”), not as easy to float a .030” tippet. For best floating performance, it is very important that the leader especially the butt, is stretched straight (same reason as for fly line). Then dress with silicone line dressing. Remember, there is no silicone leaching out of the leader, and there is no texturing magic there.
The line/leader connection is important too. For lines with very little tip flotation (2-3 wt.) use a 2-turn needle knot to connect leader butts. Heavier lines have more tip flotation, so there are more options. Then there are anglers who use a 7 to 9-turn nail knots “gooped” up with lots of adhesive to make them stronger. These knots sink like a rock, and once the knot is submerged, the whole enchilada sinks. Remember, adhesives can’t make nail knots stronger, they are compression knots. If tied “neat” and pulled completely tight (rare), nail knots can be VERY strong. When the tip end-loop is clipped off delicate lines (I prefer that), it does expose the hollow core of the line, and a bit of water can wick in. Some anglers put a small drop of some sort of waterproof adhesive on the cut end (careful re SG), and that works for a while. Properly tied nail knots (meaning, pulled completely tight) will prevent water from entering too. But even if water does get in it won’t wick far and casting the line tries to force the water out, therefore it shouldn’t become a big issue.
Finally, pay attention to the material you are using. To recap — nylon has a SG of 1.2, but fluorocarbon has a SG of 1.8. Therefore don’t use Fluorocarbon with dry flies, and expect it to float.