How to Improve Your Underwaters (3 Things That Actually Work)

It’s no secret that underwaters have taken over the swimming world.

Every meet I go to, or even just watch, I notice the same thing — swimmers are taking their underwaters farther and farther off every wall. What used to be a few quick dolphin kicks has turned into 10–15 meters of pure speed.

So why is this happening?

Because underwaters are faster than surface swimming (Well at least they can be.) Also longer underwaters = less swimming, which in hand = less swimming fatigue.

If you’re not maximizing your underwaters, you’re leaving time on the table.

Another common question is: how far are you actually allowed to go underwater?

In competitive swimming, you are allowed to stay underwater up to the 15-meter mark. If you look at the lane lines, you’ll usually see a colored marker (often red). That indicates where your head must break the surface. If your head is still underwater past that point, you can get disqualified.

So now that we know underwaters are important, the real question is:

How do you actually improve them?

From my own experience as a swimmer, I’ve found three things that made the biggest difference. These are things I personally used, and they apply whether you’re a swimmer, coach, or even a parent trying to help your athlete improve.

1. Use Drag Socks (Game-Changer)

Out of everything I’ve done, this was probably the most impactful tool for improving my underwaters.

And honestly, I didn’t even hear about them until I got to college.

Drag socks are exactly what they sound like — they’re small mesh socks that go around your ankles. The material is similar to a mesh equipment bag, and they create resistance while you kick.

At first, they feel brutal.

Your underwater kicks feel slower, heavier, and way more difficult. But that’s the point — you’re building strength in the exact movement pattern of your underwater dolphin kick.

The real magic happens when you take them off.

I remember doing sets where I’d go from using drag socks to taking them off mid-set, and the difference felt insane. It’s like your legs suddenly move twice as fast with way more power.

One set my college coach had me do was:

16 x 25
First 8 with drag socks (underwater, slower interval)
Second 8 without drag socks (underwater, faster interval)

That transition from resistance to no resistance makes your underwater feel effortless and explosive.

If you consistently use drag socks for a few weeks, you will notice a big improvement in your strength and power off the walls.

Here is a nice pair of drag socks on amazon: https://amzn.to/4rBk8YU

2. Be Consistent in Practice

This is the one most swimmers overlook.

You can’t expect your underwaters to magically improve if you only focus on them during races.

You have to make them a habit in practice.

From what I’ve seen, the swimmers with the best underwaters are the ones who treat every wall seriously — not just the fast swims.

Here are a few simple ways to build consistency:

Do at least 3–6 kicks off every wall
On fast swims, push it to 5–8+ kicks
Set a personal standard and stick to it

It doesn’t have to be perfect every time, but it has to be intentional.

One thing that helped me was mentally committing to a number before practice. For example:

“Every wall today, I’m hitting at least 6 kicks.”

When you do that every single day, it adds up fast.

Underwaters are a skill — and like any skill, they improve through repetition.

3. Tibia Raises (Underrated Strength Exercise)

This is something you can do outside the pool, and it’s one of the most underrated exercises for swimmers.

Tibia raises strengthen the front of your lower leg, which plays a huge role in your underwater kick.

Here’s how I do them:

Sit on a bench (or any elevated surface)
Let your feet hang off the edge
Place a dumbbell between your feet (vertical)
Lift your feet upward using your ankles (dorsiflexion)
Slowly lower back down and repeat

This movement directly mimics the flick of your feet during your underwater dolphin kick.

When I started doing these consistently, I noticed my ankles felt stronger and more controlled in the water.

And the crazy part is how quickly you improve.

Within a few weeks, you’ll feel a noticeable difference in both strength and endurance.

This, combined with in-water work, creates a huge advantage.

Final Thoughts

If I had to simplify everything, improving your underwaters comes down to three things:

Build strength (drag socks + tibia raises)
Be consistent in practice
Take every wall seriously

From my experience, once you start focusing on your underwaters, it’s one of the fastest ways to drop time.

You don’t need to completely change your stroke.

You just need to maximize what happens off every wall.

And in a race, that can make all the difference.