You can add yardage. You can add dryland. You can add another “tough main set.”

Or… you can steal free speed from the wall.

Underwater speed is one of the highest-return skills in swimming because it shows up everywhere: starts, turns, breakouts. And it’s one of the most overlooked because it’s hard to coach from the deck. A swimmer can look powerful underwater and still be slow (we’ve all seen the “angry dolphin” phase).

This guide will help you coach underwaters like a skill, not a superstition.

You’ll learn:

• What actually makes underwaters fast (and what doesn’t)
• The tradeoff between underwater time and underwater speed
• The most useful metrics to watch (including TritonWear’s turn rate and push max accel)
• Real sets and drills coaches actually use
• What to do in the weight room to carry speed off the wall

Why underwaters decide races (even when nobody talks about them)

Underwaters matter because they’re the one part of the race where:

• The wall gives swimmers their highest velocity
• Drag can be lower than surface swimming (less wave drag)
• Small gains repeat every length

That’s why turns and push-offs show up consistently in performance research: effective push-off force, time on the wall, and a strong streamline position are all linked to better turn performance. (Frontiers)

Coach translation:
If you can improve the first 5–7 meters of every length, you don’t need to magically “fix the stroke” to drop time.

This is the part coaches and swimmers get twisted.

Being underwater can be faster than swimming… until it isn’t.

The mistake is coaching “stay under longer” like it’s always a win.

Here’s the simple rule you can coach:
Stay underwater while your swimmer is faster underwater than they are on the surface.
Break out when that speed advantage disappears.

Example you can use with your team

Two swimmers both “go to 7m” underwater.

Swimmer A:

• Underwater time: 2.9s
• Underwater speed: high

Swimmer B:

• Underwater time: 3.6s
• Underwater speed: lower

Same distance, different race result.

Swimmer B isn’t losing because they’re “not underwater enough.”
They’re losing because they’re underwater too long at a speed that’s no longer helping.

Coach takeaway:
Don’t coach distance alone. Coach velocity and the moment it starts to decay.

The metrics that tell you what’s really happening off the wall

If you’re using TritonWear, these are your underwater coaching best friends because they let you stop guessing.

Speed underwater

What it helps you answer:
Are they actually fast underwater, or do they just look busy?

What usually improves it:

• Better streamline (less drag)
• Better kick rhythm (more effective propulsion)
• Cleaner breakout (less speed loss)

Underwater time

What it helps you answer:
How long are they underwater, and is that time productive?

Coaching use:
Pair underwater time with speed underwater and the overall time to 10m or 15m. If underwater time increases but speed drops, they’re trading the wrong thing.

Push max acceleration (TritonWear)

What it helps you answer:
How much speed are they creating at push-off?

Why it matters:
Push-off velocity is a major contributor to turn performance, and research emphasizes that generating high push-off force while maintaining a streamlined position is key. (Frontiers)

Coach language:
You can’t “kick your way out of” a soft push.

Turn rate (TritonWear)

What it helps you answer:
How quickly are they rotating and transitioning through the turn?

Coach warning:
Fast turn rate is great… unless it creates a messy push position. Some swimmers spin fast and leave the wall crooked, and then wonder why their underwaters feel like they’re uphill.

What you want:
Fast enough to be competitive, controlled enough to hit a clean foot plant and push line.

What actually makes underwaters fast (a slightly nerdy breakdown)

Underwater speed comes from four links in the chain:

1. Push quality (create speed)
2. Streamline (keep speed)
3. Dolphin kick effectiveness (sustain or build speed)
4. Breakout timing (transfer speed to swimming)

If you only coach dolphin kick and ignore the wall or breakout, you’re leaving time on the table.

Also: faster kick tempo isn’t always better. Research and coach education content frequently point out there’s an optimal kick rhythm—over-revving can reduce efficiency. (swimmingworldmagazine.com)

Coach translation:
More kicking is not the same as more speed.

You don’t need a 30-minute underwater block every day.

You need short, consistent exposures that are:

• high quality
• measurable
• repeatable

Think 6–12 minutes, 2–4 times per week (more for advanced groups, less for young age-groupers).

Below are real sets and drills that coaches actually use.

1) Streamline: the easiest speed you’ll ever coach

If streamline leaks, the wall speed disappears instantly.

Key cues:

• head neutral (look down)
• ribs down
• hands locked
• squeeze the ears
• tight line through hips

Practical drill progression:

• Push to 5m in perfect streamline (no kick)
• Then add 2–4 kicks only if the line stays clean

Set: Streamline quality
12 x 10–15m streamline push, no kick
Rest 20–30 seconds
Goal: same distance, same time, same shape every rep

This looks boring. It wins meets.

2) Dolphin kick power and rhythm (without turning it into a knee exercise)

Vertical kick is one of the most common tools coaches use to build dolphin kick power and rhythm, and it shows up in multiple coaching guides. (U.S. Masters Swimming)

Set: Vertical kick + transfer
4 rounds:

• 3 x 10 seconds vertical dolphin kick strong (10 on / 10 off)
• 2 x 25 streamline dolphin kick on the surface, build to fast
• 2 x 6 underwater dolphin kicks fast (odd reps push out, even reps push back)
  Rest 30 seconds between pieces

This is pulled straight from USMS underwater kick sets. (U.S. Masters Swimming)

Equipment options:

• Snorkel to keep the head stable
• Short fins for younger swimmers to build feel and speed without breaking rhythm

3) The “sweet spot” set (solves the speed vs time problem)

This set teaches swimmers that “more underwater” isn’t the goal—better underwater is.

Set: Kick-count testing to find the best breakout
12 x 25 from a push, easy swim after breakout
3 reps each:

• 2 kicks
• 3 kicks
• 4 kicks
• 5 kicks
  Rest 25–40 seconds

What you track:

• Underwater speed
• Underwater time
• 25 time
• Consistency of breakout

Coach payoff:
You’ll find different sweet spots by athlete, stroke, and event. This is how you individualize underwaters without turning practice into chaos.

4) Breakout timing: where speed goes to die

The breakout is where swimmers either:

• pop up too early and waste wall speed
• stay too long and surface with nothing left
• or break out like they’re climbing a ladder (first stroke kills momentum)

Drill: one-stroke breakout
From a push:

• underwater to breakout
• take 1 stroke
• stop
• reset

Set: Breakout precision
16 x 10–15m (walk back)
Underwater + breakout + 1 stroke
Goal: same breakout mark and clean first stroke each rep

This is a coaching favorite because it isolates the transition, not just the kick.

5) Turn work that actually improves underwaters (not just “more turns”)

Turns matter because wall contact time and push-off force need the right balance. Research suggests wall contact time should be long enough to generate high push-off force while the body is aligned and streamlined. (Frontiers)

Coach translation:
Rushing the wall isn’t always faster if it ruins the push position.

Set: Turn speed with quality
12 x 25 @ 45–60 seconds
Focus:

• fast into the wall (no extra glide)
• quick, clean rotation
• strong foot plant
• push into perfect streamline
• consistent breakout point

If you’re using TritonWear, this is where turn rate + push max accel become coaching gold:

• If turn rate is high but speed underwater drops, turn mechanics are likely breaking the line.
• If push max accel is low, you may need to address foot plant, wall position, or lower-body power.

Equipment that actually helps (and how to use it without wrecking technique)

Fins
Best for: speed feel, rhythm, learning a better kick shape
Use: short fins, and keep standards high (no bicycle knees)

Snorkel
Best for: streamline integrity and kick mechanics without breathing disruptions
Use: great for younger swimmers who lose line when they breathe

Cords or resisted kicking
Best for: power development in advanced swimmers
Use: short distances, full rest, no form breakdown

Note:
If equipment makes the swimmer bend at the hips or lose line, it’s not helping. It’s just loud.

Weight room: what carries over to faster underwaters

Underwater speed isn’t only “core strength.” It’s power plus control.

You need:

• explosive push ability
• body stiffness to hold line
• ankle strength and mobility for a better fin shape

Swimming World coaching content highlights research-backed emphasis on ankle improvements for better dolphin kick performance. (swimmingworldmagazine.com)

What to train (practical and coach-friendly)

Lower-body power (push max accel support)

• trap bar deadlift (strength + power)
• squat jumps
• split squats (single-leg force)
• box jumps (quality reps only)

Core control (streamline)

• hollow holds / rocks
• dead bug variations
• Pallof press / anti-rotation work
• overhead carries (teaches line)

Ankles and feet (underwater kick efficiency)

• calf raises (straight knee + bent knee)
• tibialis raises
• banded plantar flexion work
• ankle mobility with control (not just floppy stretching)

If you want a simple template:
2 sessions/week in-season
2–3 lifts + 1 jump + core + ankles
Keep it short, fast, high quality

How to measure progress without drowning in data

Pick one “underwater KPI set” per week and track it consistently.

Best options:

• the kick-count sweet spot set
• the turn 25 set with fixed breakout point
• a 15m underwater time trial with full rest

What you’re looking for over time:

• speed underwater improves
• underwater time becomes more consistent (less variation)
• push max accel improves (stronger exit speed)
• turn rate improves without sacrificing underwater speed

Consistency matters more than one hero rep.

The bottom line

Underwaters aren’t a breath-holding contest.

They’re a speed skill.

Coach the chain:
push
line
kick
breakout

Measure what matters. Keep it simple. Repeat it weekly. And enjoy the weirdly satisfying moment when your swimmers realize their fastest swimming happens before they take a stroke.

FAQ: Underwater speed (quick answers)

How many dolphin kicks should swimmers do off each wall?
Enough to stay faster underwater than they are on the surface. For many swimmers, that’s 3–6 kicks, but it varies by athlete, stroke, event, and fatigue. Test it.

Is going farther underwater always better?
No. If speed decays below surface speed, they’re giving away time.

What’s the best drill to improve dolphin kick?
Vertical kick plus immediate transfer to underwater kicking is one of the most common, effective combinations used by coaches. (U.S. Masters Swimming)

What equipment helps the most?
Fins (for speed feel and rhythm) and a snorkel (for line control) are the most universally useful for club swimmers.

What matters more: turn speed or push power?
Both. You want quick rotation into a strong, aligned push. Research emphasizes push-off force, wall time, and streamlined position as key to better turn outcomes. (Frontiers)

Want to learn more about the TritonWear data that can help you drive faster underwaters?