Sinking fly lines are a complex subsect of the fly fishing world. The different grain weights and sink rates are much more complex than traditional floating lines. If you’re trying to figure out what line you need, check out our recent overview of the different lines available. Once you’ve figured out what line suits you best, it’s time to hit the water. While it may seem straightforward, there is a lot more to fishing these lines than it first appears. To shorten the learning curve and get your flies down where they need to be, we created this guide to fishing sinking fly lines. We cover the tactics, scenarios, and retrieves necessary to keep your fly in the strike zone.
Stillwater:
Stillwater fisheries are exactly what their name implies: bodies of stagnant water—lakes, ponds, and reservoirs—where fish are cruising around rather than holding in current. If you’re targeting fish in stillwater, there is no need to overcomplicate fishing a sinking line. Without any real current to meddle with your fly and the fly line’s descent through the water column, you can simply count down your fly to the desired depth. If your line is rated for 6 inches per second (IPS), then every second equates to roughly six inches of sink.
Don’t forget to take into account the weight of the fly you are fishing. A heavy, weighted fly will add to the overall sink rate. While each fly will behave a bit differently based on the materials it’s tied with, profile, etc, you can still do some quick math in your head to determine which depth you’re fishing at. For example, if given 10 seconds, a 4 IPS line will descend 40 inches, or about 3 ½ feet below the surface. I personally like to commit to fishing my fly at one depth for a dozen or so casts and then switch up my countdown in order to fish the fly higher or lower in the water column. When my streamer gets smoked— that’s the sweet spot. A Clouser will, of course, sink faster than a bulky deceiver, so be sure to consider your fly choice as well.
A great way to get a precise understanding of how your sinking line behaves is to simply watch it—especially if the water clarity is decent. Get up on some structure, whether shore fishing or up on the bow of your vessel, for a better-viewing vantage, and carefully examine how and when your fly line descends into the depths. Seeing is believing, right?
Remember that casting an aggressive sinking line is a lot more work than a slower-rate sinking line or sink tip, so take some time to consider what will get you down into the zone without having to exert yourself more than necessary. A 2-3 IPS line will get down deep if you allow it to, especially if it’s a full sinking line without a floating running line section. If you’re targeting fish below the 8-ish foot mark, a full sinking line gives you the best connection to your fly. While a sink tip may be able to get you into the zone, if your running line is on the surface, your fly will only stay that deep in the water column for a few strips before arking upwards back to you. A full sinking line with a few different rates of sink through the shooting head/running line almost eliminates the hinge effect of the line, resulting in better strike detection and line sensitivity/feel in general. In short, if you’re going deep in stillwater, opt for a full sink so you can maintain a nice connection to your fly and keep it down in the zone longer.
Stream Fishing and High Current Scenarios:
Introducing even a mild current into the equation is where things certainly get a bit more technical regarding sinking line tactics. Moving water, whether it be a river/stream flow or tidal current, will affect your fly line’s ability to descend unhampered. The greater the stream CFS, tidal current, or wave wash, the more sinking power you’ll require to get your fly down into the column. If you’re a floating line aficionado on the stream trying to wrap your head around sinking line rates, think more split shot and heavier flies when nymphing a fast, deep pool.
As soon as your line is straightened out and taken by the current, your fly will respond accordingly, so there are a few methods you can employ to get deep and stay deep. We already discussed how upstream mends, when utilizing a sinking tip, can give your fly more time to drop, so be sure to play around with that technique.
Trout streamer fishing requires throwing large flies and quickly getting them down to the strike zone. You are looking for a predatory response, so stick with quick, repeated casts. The “zone” you strip your flies through may be as short as 3-4 feet wide. In these scenarios, anglers can get away with a sinking line with a heavier density. The heavier IPS ratings will get your fly where it’s needed for these quick retrieves.
While striper fishing the tidal rips from a boat in moderate current scenarios here on my home water on Cape Cod, I often shake out an additional 5-10 feet of running line to allow the more aggressive sink rate section of my full sink to really get down there. The current is moving swiftly but not so fast that the line I shake out immediately gets swept away, so I’ve found this is a solid way to drop my squid and bunker patterns closer to the bottom where the fish are often holding.
Once again, keeping an eye on your fly line’s scope and behavior is arguably the best way to envision how your fly is behaving down there, so pay attention and gather all the data you can through simple observation.
Fishing the Surf and Wave Action
Fishing the surf can be some of the most rewarding DIY fishing. Big striped bass or snook cruising along sand bars and shoals offer excellent chances at true giants for those stuck to land. While water depths can vary, most beachside eats take place in relatively shallow water. Rather than a full sinking line, intermediate lines are the go-to choice for surf anglers.
The biggest factor beach anglers face is wave action. When battling rough surf, floating lines will get tossed around, resulting in slack lines and a poor connection to your fly. Intermediate lines sink just below the waves, enabling you to maintain a tight line and consistent retrieve. In addition, this slow sink rate, when paired with a properly weighted fly, will keep your pattern down where the fish are. With the fly protected from waves and in the strike zone, anglers can fish how they want.
Other Details to Consider:
Fly Movement:
Whether you’re targeting fish 5 or 15 feet under the surface, it’s also important to think about how your fly will behave based on different sinking line setups. The main factor here is the retrieve path between sink tips and poly leaders vs. full sinking lines and intermediate lines. A fly line with a sinking head or tip section only (sink tips and polyleaders) will tend to draw the fly off the bottom and upwards towards the floating running line sooner, so be sure to keep this in mind when trying to imitate the prey item you’re casting. Crawdads, various shrimp species, and crabs, for example, typically flee from predators downwards into the bottom structure or substrate rather than upwards or outwards, as a fleeing baitfish might do. If you’re attempting to imitate a prey item that burrows or evades predation by shooting down, you’ll want a full sinking line to best replicate this behavior. Simply put, a full sinking setup will allow you to better dredge your fly and stay deeper longer if the anticipated strike zone is on the bottom. Furthermore, the faster the sink rate, the faster you’ll be able to strip your fly without it coming off the bottom, so if fast retrieves are pivotal for producing bites in your fishery, keep this detail in mind as well.
Fishing from Shore vs. a Boat:
A factor that’s easily overlooked is where you’re casting from. You may find value in a sink tip rather than a full sinking setup if you’re wade fishing and making long casts to reach the deep water over a shelf. By employing a floating running line, your fly will theoretically come off of the bottom and avoid unwanted snags if you’re fishing it back to you over shallow structures or weeds. Alternatively, if you’re already out in the deep water on a vessel or shore fishing off a ledge with no skinny water to worry about hanging up on, you’re free to forget this detail.
Final Thoughts
We’ve waded through quite a bit of info here, so let’s end on a few key takeaways.
It’s worth experimenting with a few different sink rates/styles: Remember that sometimes the difference between producing bites can be as little as a few extra feet of depth, so it’s worth testing out some different line options. A 6 IPS full sink vs. a 4 IPS sink tip could very well be the difference that punches your fly through the swift tidal current or stream flow and suddenly puts you in the strike zone, so recognize that trying different sink rates and style lines could potentially blow your fishery wide open!
Practice makes perfect: If you’re new to casting sinking lines, there will be a learning curve, so be patient with yourself. These lines can be awkward, strenuous, and sometimes even sketchy to cast, so give yourself some grace while learning the casting dynamics of a new fly line. This is also yet another reason to explore your options and experiment with some different sinking lines – you may find one that nicely clicks with your muscle memory for whatever reason.
Extra spools are your friend: Let’s be real here – putting together a whole other fly fishing setup isn’t cheap, so consider the benefit of buying an extra spool or two for your existing reel in order to quickly and easily swap out lines. An extra spool also, of course, packs lighter and more compact than an additional reel if pack space or weight is crucial to your style of fishing.
Don’t overthink it: While we only scratched the surface of tactics and techniques, and there are countless factors and nitty-gritty details to consider when fishing a sinking line setup, sometimes it can be helpful to take a step back from the science of it all and just fish. There’s a time to be technically minded, and there’s a time to just let it rip and be mindful of your results, so don’t forget to see the value in some good ol’ fashioned trial and error.