Master the 15-Meter Rule: The Underwater Technique That Wins Races

Who This Is For

Imagine you're at a swim meet, you push off the wall, and you glide underwater while your competitors pop up immediately. You feel the rush of passing them without even swimming. That's the power of the underwater phase—the most underrated technique in competitive swimming. This guide is for any swimmer who wants to shave seconds off their times by mastering the rules and techniques of underwater swimming.

I'm not a coach, but I've studied the rulebook inside out, and I can tell you this: most swimmers surface way too early. They're leaving free speed on the table. The key is the 15-meter rule—a rule that applies to every stroke and can make or break your race.

Know the 15-Meter Rule

World Aquatics, the governing body for swimming, states that in all strokes, a swimmer may stay fully underwater for no more than 15 meters after the start and each turn (World Aquatics). That's your legal limit. But here's the thing: most swimmers only use 10 or 12 meters. They're wasting 3 to 5 meters of free speed.

Why is underwater swimming so fast? Because you're in a streamlined position, and you can use powerful dolphin kicks that are faster than most strokes. The water resistance is lower when you're fully submerged, and you're not fighting the surface waves.

Stroke-by-Stroke Underwater Tactics

Each stroke has its own rules and techniques for the underwater phase. Let's break them down.

Freestyle and Backstroke

In freestyle, you can use a flutter kick or a dolphin kick underwater. Most elite swimmers use a dolphin kick because it's more powerful. In backstroke, you must remain on your back except during turns, and you can also use a dolphin kick. The key is to stay underwater for the full 15 meters, then surface smoothly without breaking your momentum.

For backstroke, remember that your head must break the surface at or before the 15-meter mark, and then you must stay on the surface until the next turn or finish (World Aquatics Swimming Rules Reference Card). Also, in backstroke, you can be completely submerged within the final 5 meters while reaching for the finish—a detail many swimmers forget and can use to their advantage.

Breaststroke and Butterfly

Breaststroke is trickier. You're allowed one butterfly kick during the first breaststroke kick after the start and each turn (World Aquatics). That's it. After that, you must use a legal breaststroke kick. Your head must break the surface before your hands turn inward at the widest part of the second stroke after the start or turn (World Aquatics Swimming Rules Reference Card). So you can't stay underwater for long.

Butterfly is different. You can use a powerful dolphin kick underwater, and you have the same 15-meter allowance. Butterfly is the second fastest stroke after freestyle and is often considered the most difficult to master (Britannica: Butterfly). But once you get the rhythm, the underwater phase is where you can gain on your competitors.

The Turn: Where Races Are Won

Turns are the other half of the underwater equation. A bad turn can lose you a meter; a great turn can gain you a meter. Here's how to nail each stroke's turn.

For freestyle and backstroke, you can do a flip turn. In backstroke, the turn must start immediately after turning onto your breast at the completion of the arm pull, touch the wall, and leave on your back (World Aquatics Swimming Rules Reference Card). For breaststroke and butterfly, you need a two-hand touch. In breaststroke, you must touch with both hands simultaneously, and you can then use that one butterfly kick to push off.

One common mistake is gliding too long into the wall. You want to initiate your turn before you slow down. Practice your turns until they're automatic, and you'll see your times drop.

What Can Go Wrong: Disqualification Landmines

Nothing is worse than a DQ. The rules are strict, and officials are watching. Here are the infractions that can end your race:

• Standing on the bottom of the pool is an infraction except in freestyle events (World Aquatics Swimming Rules Reference Card).
• Pulling on the lane rope during a race is an infraction (World Aquatics Swimming Rules Reference Card).
• Obstructing another swimmer during a race is an infraction (World Aquatics Swimming Rules Reference Card).

In backstroke, if you turn onto your breast before the wall, you're DQ'd. In breaststroke, if you take a butterfly kick during the stroke, you're DQ'd. In butterfly, if your legs alternate, you're DQ'd. The list goes on.

Quick tip: In relays, the outgoing swimmer's feet must remain in contact with the starting platform until the incoming teammate touches the wall (World Aquatics Swimming Rules Reference Card). A fraction of a second early and your team is disqualified.

My Recommendation: Drill Your Underwater Phase

Here's my point of view: the single most important technique to improve is your underwater phase. Not your stroke, not your breathing—your underwater kick. Spend at least 10 minutes every practice doing underwater dolphin kick drills, working on staying streamlined and maintaining speed.

Compare the strokes' underwater allowances:

Notice that breaststroke is the exception—you can't stay underwater as long because of the head-breaking rule. But for the other three, you have the same 15 meters. Use it.

Bottom Line

If you take one thing from this article, it's this: master the 15-meter underwater phase. It's legal, it's fast, and it's the easiest way to gain an edge without changing your stroke. Practice your dolphin kick, work on your turns, and you'll be amazed at how much time you drop.

Sources

• World Aquatics - https://www.worldaquatics.com
• World Aquatics Swimming Rules Reference Card (2023-2025) - https://eastswimming.org/wp-content/uploads/2024/04/WA-Swimming-Reference-Card_13072023-Large-Print-Bold.pdf
• Britannica: Butterfly (swimming) - https://www.britannica.com/sports/butterfly-swimming
• NBC Olympics: Swimming 101 Equipment, swimsuits and pool dimensions - https://www.nbcolympics.com/news/swimming-101-equipment-swimsuits-olympic-pool-dimensions