Ask MidCurrent: How Can I Make My Dry Flies Float Better and Longer?

Question: I love dry-fly fishing, but I find that my flies often don’t float very well and get waterlogged quickly. What’s the secret to keeping a fly on the surface?
—Emily B., Whitefish, MT (via the Ask MidCurrent form)

Answer: Fly fishers often struggle to keep dry flies floating on the surface, especially in riffles and fast-moving currents. In turbulent water, flies can get waterlogged or pulled under quickly. Fortunately, there is a range of products and techniques designed to keep flies riding high for longer. Here’s pretty much everything you need to know about what you can do and which products you can use to ensure a longer, better float.

Gel Floatants (Silicone Gels & Pastes)

Gel floatants are the most popular, all-purpose solution to keep dry flies afloat. These are silicone-based gels or paste-like dressings that you rub into a dry fly’s body, hackle, and wings. The gel coats the fibers with a hydrophobic layer, preventing water from soaking in. In effect, you’re waterproofing the fly, so it rides on the surface tension longer.

Always apply gel floatant before the fly ever touches water, when the pattern is still bone dry, such as right after you tie it on. This will allow the floatant to be absorbed more thoroughly, making it last longer. Some anglers even pre-treat their flies the night before a trip, allowing the floatant to fully soak in and dry.

Use only a small drop of gel, and gently massage it into the fly’s materials with your fingertips. Work it into all the hair, hackle, and dubbing, as any spot you leave untreated can absorb water and sink. That said, don’t overdo it: too much gel can gum up hair and hackles or make the fly ride unnaturally. Do not use gel floatant with CDC (cul-de-canard) feathers, because it will mat the CDC and actually cause the fly to sink faster.

You can also rub a bit of gel floatant on the tippet section near the fly. This keeps your tippet from sinking and pulling the dry fly under.

In fast-moving water, a good gel floatant is your first line of defense. Apply it to a fresh fly before fishing, and it will significantly delay waterlogging. Just remember that no floatant lasts forever. Eventually, the fly will start to sink after enough casts or fish strikes. At that point, it’s time to dry and re-treat the fly using the methods below.

Powder Floatants (Dry Dust & Brush-On Powders)

Powder floatants are dry, water-repellent powders (often made of amorphous silica or similar) that help dry a fly and coat it with a fine dusting of hydrophobic particles. They serve two purposes: they can dry out a damp fly and also add buoyancy by trapping tiny air bubbles among the fibers. Some powders come in a shaker bottle, while others are applied with a brush or drop-in dip.

Powder floatants are especially useful after a fly has seen some use, for example, if your dry fly starts to ride lower after 10–15 casts or after you’ve caught a fish and the fly is slimy. You generally don’t use powder as the initial treatment. (Start with gel for that.) Instead, think of powders as a mid-stream refresher to restore flotation. They are also the preferred treatment for flies tied with CDC. Because powders are dry, they won’t mat the CDC fibers.

There are two common application methods: Products like Frog’s Fanny or Loon Dust come with a small brush. You dip the brush, lightly dust the powder onto the fly’s body and wings, and then brush off any excess. This is great for targeted application (e.g. on a small fly or specific areas). It’s less messy and wasteful than shaking. These powders work on slightly damp flies or freshly slimed flies. It helps if you first blot or false-cast the fly mostly dry, and then brush on the powder to suck up remaining moisture and coat the fly. Powders work wonderfully on CDC puffs, Comparaduns, and other delicate dry flies.

Dip or Shake Powders are bottles (often labeled “Dry Shake”) filled with powder; you drop the fly in and shake. The powder envelops the fly completely. This is quick and effective, but it can waste more powder and create a cloud of dust when you open it. (Be careful using shake powders on a windy day, as the excess will blow around.) You simply place the soaked fly (still on tippet) into the container, close it, and shake for a few seconds. Pull the fly out, tap or blow off the extra powder, and it should look crisp and dry again.

Powder floatants shine in fast water when you need to quickly rejuvenate a sinking fly. However, they don’t last as long as a gel treatment. After a few casts, the dust may wear off and water can creep back in. It’s common to get maybe 5–10 good drifts after using a powder desiccant, and then you’ll need to shake again. This can vary with fly size and river conditions; for instance, bushy flies in turbulent water might need more frequent attention.

Desiccant Shakes (Fly Drying Agents)

“Desiccant” floatants are closely related to the powders above. In fact, most shake-style floatants are a blend of desiccant and powder. The term desiccant means a drying agent (think silica gel packets). In fly fishing, desiccants are usually water-absorbing crystals or granules in a bottle. When you drop a soaked fly into them, they actively suck the moisture out of the fly’s materials, restoring buoyancy. If a product’s instructions say “shake your fly inside the bottle,” it likely has a desiccant component. If it’s a brush-on, it’s mostly just powder.

Use a desiccant shake as soon as your fly starts to sink or after it’s been slimed by a fish. In moving water, a high-floating dry can suddenly get dunked by a swirling current or dragged under by your line. As soon as you notice your fly isn’t floating properly, strip it in and give it a quick drying treatment. Fish slime will sink a fly almost instantly, even one treated with gel. A few shakes in a desiccant will remove the slime and dry the fly for reuse. Carry the desiccant bottle somewhere handy, such as on a zinger on your vest or chest pack for quick access.

Without removing the fly from your line, open your desiccant bottle, drop the fly in (still attached to tippet), close the lid, and shake vigorously for 5–10 seconds. The shaking action embeds the drying crystals into the fly. Then take the fly out and knock off any excess powder with a gentle blow or tap. The fly should come out dry, lightly dusted, and ready to float again. You’ll often see a bit of white residue, which is fine and will disappear on the first cast. After treatment, get the fly right back on the water and fish on.

Keep in mind, a desiccant revive is temporary. In continuous fast currents, you may end up doing frequent quick shakes. If you find you’re having to dry the fly every few casts, it might be time to switch to a fresh fly.

No matter which product you choose, frequent use of desiccant in moving water is key. Don’t hesitate to dry your fly often. Trout in fast water can strike hard – if your fly is saturated or sinking, you’ll miss those takes because the fly isn’t where it should be (on the surface). Keeping it high and dry will improve your hookups.

Liquid Floatants and Spray Pre-Treatments

In addition to gels and powders, there are liquid floatants and sprays that can be very useful. These typically come in a bottle, and the idea is you dip or spray the entire fly to coat it with a very thin, even layer of floatant. Often the liquid contains a volatile solvent: after you dunk the fly, the liquid evaporates leaving behind a waxy or silicone residue on the fly’s fibers. This is akin to a “deep soak” of floatant.

Liquid floatants are great as a pre-treatment for flies ahead of time. With a product such as Fly-Agra or Loon Hydrostop, you dip a new fly and then let it dry for a few minutes (or even overnight). Once dry, that fly is thoroughly waterproofed. This can make a huge difference in fast water, because the fly will float significantly longer before it ever starts to sink. Before a day of fishing a heavy hatch, you might pre-treat a half dozen dries (especially smaller mayflies) with a liquid so they’re ready to go.

You can also use liquid floatants streamside by dipping your fly and then false-casting it dry. You simply dunk the fly in the bottle, pull it out, and give a few quick false casts to dry off the excess. Once it’s done, that fly will float for a much longer than it would with just a gel treatment.

For a dip floatant, just remove the cap, dip the fly (holding onto your leader) so that the fly is fully submerged, and then withdraw it. Gently shake off or flick away the big droplets, and either let it air dry for a minute or do a few false casts until the fly is just slightly damp. The solvent will evaporate, leaving the floatant embedded in the fly. For spray treatments, hold the fly (or multiple flies on a piece of foam) and spritz them lightly, then let them dry thoroughly (often 24 hours for maximum cure).

Liquid floatants have a few advantages. They tend to coat very evenly, and you don’t have to get your fingers messy because you dunk or spray without rubbing the fly. One caution: Avoid using a liquid floatant on a fly that is already waterloggedbecause the water blocks absorption. Dry the fly first or use a desiccant before re-dipping. Also, like gels, most dips are not CDC-friendly unless specifically stated.

Patterns that incorporate deer hair, foam, and lots of hackle will generally float longer. Flies courtesy Fulling Mill

Ways You Can Help a Fly Float longer

In addition to modern products, it pays to use some common-sense fly care techniques on the water. These can greatly extend your dry fly’s performance in a river:

• False Cast to Dry the Fly: If you see your fly starting to sink, make a few quick false casts in the air. The wind resistance will help shake water off the fly. This is effectively “air drying” the fly between drifts. A couple of firm false casts can often perk a fly back up for a few more drifts. After using a powder or desiccant, always give the fly a brisk false cast to blow off excess dust. It’ll also help “set” the powder into the fly.
• Blot or Squeeze Water Out: Many anglers carry an absorbent patch or simply use their shirt. Gently squeezing the fly in a piece of absorbent material can wick a lot of water out. The classic tool for this is an amadou patch, made from a natural tree fungus that’s extremely absorbent. By pressing a soaked fly between two amadou patches, you can suck out moisture and prepare it for fresh floatant. Amadou is excellent for drying CDC flies without damaging them. Always blot—don’t grind the fly—to avoid tearing feathers or hackle.
• Keep the Fly Clean: Mud, algae, or fish slime on a fly will hasten sinking. If your fly accidentally lands in the mud or gets slimed, rinse it off in the water, then dry and re-treat it.
• Leader Management: In fast water, drag is your enemy. If the current catches your line, it will pull the fly under, no matter what floatant you use. Good mending, line management, and keeping as much line off conflicting currents as possible will help your fly float naturally.
• Use High-Floating Fly Patterns: In swift rivers, consider using dry flies tied with buoyant materials, such as foam bodies, deer-hair wings, or oversize hackle. Adding floatant to an already bushy, buoyant fly can keep it riding for dozens of casts, whereas a sparse fly might sink sooner. If you’re trying to match a hatch, you might not have this luxury, but whenever possible choose a fly suited for the water conditions.
• Know When to Retire a Fly: No matter what you do, a fly will eventually become so waterlogged or slimed that it just won’t float. If you’ve dried it and treated it multiple times and it’s still drowning, swap it out for a fresh fly, and put the soggy one aside to dry properly. This is why it’s wise to carry a few extra of each dry pattern.