Butterfly Kick Rules: The 15-Meter Myth and Other Stroke Technique Truths

Can I swim underwater the whole race?

No, and if you try, you'll be disqualified. In every stroke, you can stay fully submerged for no more than 15 meters after the start and each turn (World Aquatics). That's a hard rule, not a guideline. We've seen swimmers push that limit and get called for it. The 15 meters is measured from the wall, not from where your head breaks the surface. So if you're doing a butterfly or freestyle underwater dolphin kick, you need to surface before that mark or you're out.

For backstroke, there's an extra twist: 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). The only exception is the final 5 meters before the finish, where you can be completely submerged while reaching for the wall. That's a technique we teach our sprinters—stay underwater as long as legal, then come up and finish strong.

Is it true that you can't stand on the bottom in a race?

Yes, but only in pool swimming. Standing on the bottom is an infraction in all strokes except freestyle (World Aquatics Swimming Rules Reference Card). That's a rule that surprises a lot of new swimmers. In freestyle, you can actually stop and stand if you need a breather—though we'd never recommend it in a race. In backstroke, breaststroke, or butterfly, touching the bottom with your feet is a disqualification. We've seen swimmers try to push off the bottom at a turn—that's also illegal. The only time you're allowed to stand is in open water, where the rules are different: you can stand on the bottom, but you can't walk or jump (World Aquatics Open Water Swimming Rules).

Does the one-false-start rule mean I get one warning?

No, that's a myth. The one-false-start rule means that a single false start results in disqualification (World Aquatics). There's no warning—if you leave before the starting signal, you're out. That's been the rule for years. We always tell our swimmers: treat every start like it's the only one you get, because it is. The old rule used to allow one false start per race, but that changed. Now, any false start is immediate DQ. So don't test the starter—wait for the gun.

What's the deal with the butterfly kick in breaststroke?

This is one of the most misunderstood rules. In breaststroke, you're allowed one butterfly kick during the first breaststroke kick after the start and each turn (World Aquatics). That means you can do one dolphin kick before your first breaststroke kick, but only one. After that, any downward butterfly kick during the stroke is not permitted (World Aquatics Swimming Rules Reference Card). We see swimmers try to sneak in two or three dolphin kicks off the wall—that's a DQ. The rule is strict: one kick, then you're into the regular breaststroke rhythm.

Also, 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). That's a timing thing that takes practice. And remember, your elbows must stay under the water, and your hands can't go back beyond your hip line. We drill these details constantly because they're easy to miss in a tight race.

Is backstroke the easiest stroke to swim legally?

Not at all. Backstroke has some of the trickiest rules, especially around turns. You start in the water, which is unique, and you must stay on your back except during turns (World Aquatics). The turn is where swimmers get disqualified: you must turn onto your breast immediately after the arm pull, touch the wall, and leave on your back (World Aquatics Swimming Rules Reference Card). If you do a flip turn without touching the wall, or if you push off on your side, you're out. Also, you can't be completely submerged for more than 15 meters after the start or turn, as we mentioned. So it's not just about staying afloat—it's about precise timing and body position.

Can I wear a tech suit for every race?

No, and you shouldn't. World Aquatics banned high-tech swimsuits effective 1 January 2010 (NBC Olympics). The suits must be textile-only, with men's suits from waist to knees (jammers) and women's from shoulders to knees. Every approved suit has a World Aquatics tag. The ban came after 43 world records were broken at the 2009 World Championships, dominated by high-tech bodysuits. We've all seen the old LZR Racer suits that were used at the 2008 Olympics—they were revolutionary but unfair. So now, if you show up with a suit that doesn't meet the standards, you're disqualified. We always check the tag before a meet.

Quick tip: Practice your turns

Most technique DQs happen at turns. Spend extra time on your turn technique—it's where you gain speed and where you can lose it all with an infraction.

Bottom line

The best move you can make is to learn the exact rules for your stroke. Know the 15-meter limit, the touch requirements, and the turn rules. Then practice them until they're automatic. That's what separates a fast swimmer from a disqualified one.

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
• NBC Olympics: Swimming 101 Equipment, swimsuits and pool dimensions - https://www.nbcolympics.com/news/swimming-101-equipment-swimsuits-olympic-pool-dimensions
• World Aquatics Open Water Swimming Rules - https://www.aquaticapaulista.org.br/arquivos/2025/2025082012255.pdf