How to Fix Your
Underwater
Dolphin Kick

The underwater phase after every start and turn is where races are actually won and lost. Most swimmers know this. What most swimmers don't know is why their dolphin kick isn't as fast as it should be — and the answer is almost never effort.

I spent 18 years competing internationally, held 18 American records, and the underwater dolphin kick was my weapon. I've also spent thousands of hours watching other swimmers' underwater mechanics. The same mistakes show up everywhere — from age groupers to national-level athletes. Here's what they are and how to fix them.

Mistake #1: Kicking from the Knees

This is the most common problem I see. The swimmer bends at the knee first, drives the lower leg, and gets a small, choppy kick with almost no propulsion. It looks busy but it's slow.

A powerful underwater dolphin kick is initiated from the hip and core, not the knee. The whole body acts as a wave — hips drive the motion, the knee bends as a consequence, and the foot snaps at the end. Think less "leg kick" and more "body undulation that ends with a foot snap."

The fix: Press your chest down slightly and feel your hips drive upward first. Exaggerate it. Your kick will feel slower initially because you're generating a bigger amplitude — but the power transfer is dramatically higher.

Mistake #2: Too Much Amplitude, Wrong Timing

Some swimmers over-correct and go huge — giant undulations that look powerful but create too much drag on the recovery phase. Big amplitude only works when the body stays tight.

The key is streamline integrity. Your arms must stay locked — hands stacked, biceps squeezing the ears, core braced — or all the power you generate through the kick leaks out through a soft upper body. A loose streamline is like trying to push a rope.

The fix: Overlap your thumbs and press. This forces your shoulders to internally rotate and your lats to engage. Now your upper body is a rigid platform for the kick to work against.

Mistake #3: Ignoring Ankle Flexibility

This one gets overlooked constantly. Your foot is the final propulsive surface in the dolphin kick — it's where the power you generated through your hips and core actually exits your body and pushes the water. If your ankles are stiff, you're losing a huge percentage of that energy right at the end of the chain.

Elite dolphin kickers almost universally have exceptional ankle plantarflexion — the ability to point the foot fully and hold it there under load. Most swimmers have never specifically trained this. They stretch their hamstrings, their shoulders, their lats — and completely ignore the joint that's doing the final work underwater.

The fix: Add ankle mobility work to your daily routine. Seated ankle circles, resistance band plantarflexion holds, and kneeling ankle stretches before practice all help. For a quick in-practice drill: kick on your back with fins, focusing on feeling the fin load through a fully pointed foot. Then take the fins off and try to recreate that same sensation. Flexible ankles are trainable — most swimmers just never bother.

Mistake #4: No Acceleration into the Wall

Most swimmers coast into their turn and then try to explode off the wall. The best underwaters start before the touch. Your last two or three kicks into the wall should be accelerating — so you're already moving fast when you push off.

The fix: Count your kicks on every underwater in practice. Know your number. Then consciously make your last two kicks sharper before the touch. This is a habit, not a talent.

Mistake #5: Not Going Deep Enough Off the Turn

Most swimmers push off the wall and stay shallow — hovering just under the surface and kicking out from there. It feels controlled. It's leaving free speed on the table.

The move off a turn is to push off with a slight downward angle and let buoyancy do the work on the way up. When you're a few feet below the surface, the water's natural upward pressure starts pulling you toward the surface as you kick. You're not muscling your way up — you're riding the water. That buoyancy force adds to your forward momentum instead of just being something you punch through.

Think of it like a ramp built into the physics of water. You push off, go slightly down, kick hard, and the water carries you up into your breakout. The rise feels effortless because it partially is.

The other benefit: deeper water off the turn is less turbulent. The churn from the touch is at the surface. A foot or two deeper and you're in clean water, which means your dolphin kick is working against undisturbed water the entire way out.

The fix: On your next set of turn reps, consciously aim your push-off slightly down instead of flat. Get below the chop, establish your kick, and feel the water start pulling you up as your speed builds. That rising sensation — buoyancy working with you — is what you're after. Once you feel it, the flat turn-and-kick feels like a waste.

What to Work on First

Don't try to fix all five at once. Start with the hip initiation — mistake #1. Everything else gets easier once the kick is being generated from the right place. Spend two weeks on that before adding anything else.

Underwater mechanics are one of the highest-leverage things you can improve as a competitive swimmer. Unlike stroke technique, which has dozens of variables, the dolphin kick is relatively simple — body wave, tight streamline, timing. It's learnable at any level.

Work on It in Person

Reading about dolphin kick mechanics and actually feeling the correction are two different things. At our swim camps in California, underwater technique is a core focus area — I get in the water with athletes and give real-time feedback on exactly what I see. We keep groups small so every athlete gets direct coaching, not just a demonstration from the deck.

If you want one-on-one work, private lessons are the fastest way to fix your underwater. The dolphin kick is where I made my career. It can be where you make yours.