Why swimmers wear two swim caps in races
By Rive News / Research desk | Rive News / Published October 28, 2026 at 9:00 AM PKT
Key takeaways
- Two caps sandwich the goggle straps, so the goggles stay put through dives and turns.
- The usual order is a latex cap, then goggles, then a silicone cap on top.
- The outer silicone cap stays smooth, which trims drag on the head, the first part of the body to cut the water.
[A swim cap in close view, showing its smooth shape.] Photograph: Wikimedia Commons contributor
Image Credits: Wikimedia Commons
Swimmers wear two swim caps to solve two small problems at once. The first is keeping goggles secure during a dive. The second is keeping the head as smooth as possible through the water.
The trick is in the order. A swimmer puts on a latex cap, places the goggles over it, and then pulls a silicone cap over the whole arrangement. The goggle straps end up trapped between two layers of rubber, and the smooth outer cap covers the straps entirely.
This article explains the layering order, why the two materials differ, how much such margins matter in elite racing, and where the trick reaches its limits.
The layering order, step by step
The inner cap is usually latex. Latex grips the head well and stays put, but it wrinkles and bunches more easily than silicone. On its own, it is a weaker race-day choice for the outer layer.
Goggles go on next, with their straps sitting over the latex cap. This placement matters because the straps need something to grip, and a bare head gives them less purchase than a rubber cap does.
The outer cap is usually silicone. Silicone is smoother and holds its shape better, so it presents a cleaner surface to the water. It also presses the goggle straps flat against the head, which stops them from shifting when the swimmer dives in.
Dave Salo, an assistant coach for the 2012 United States Olympic women's team, explained the material point to Yahoo Sports during the London Games. "The outer silicone cap better maintains the shape and does not wrinkle as much, thereby causing less drag," Salo said.
Why goggle security matters so much
Losing goggles mid-race is worse than losing a cap. A swimmer who cannot see the wall, the lane rope or the turn must guess, and a flooded pair of goggles can end a medal chance outright.
Dives put the most stress on the arrangement. The impact of entering the water at speed can shift straps, and turns add further jolts as the swimmer pushes off the wall. Trapping the straps between two caps gives them far less room to move.
Caps still come off sometimes. Dana Vollmer won gold in the 100 metre butterfly at the 2012 London Games despite one of her caps coming off during the race. Her win shows the trick helps rather than guarantees, and that a lost cap is survivable when the swimmer keeps composure.
American swimmer Emma Weber lost a cap at the Paris 2024 Games, in a moment widely shared because a spectator jumped in to retrieve it. The incident underlines a simple point: even elite setups fail occasionally, and the second cap is insurance, not magic.
Why tiny drag savings are worth chasing
Elite swimming is decided by hundredths of a second. At the Paris 2024 Games, Britain's Adam Peaty took silver in the men's 100 metre breaststroke, missing gold by three hundredths of a second.
A wrinkled cap or an exposed goggle strap adds drag at the very front of the swimmer's body. The head leads every stroke, so roughness there costs more than roughness further back. Smoothing it is cheap, legal and repeatable, which is why so many elite swimmers adopt it.
Katie Ledecky, the American distance star, wore two caps in her 1500 metre freestyle heat at Paris 2024. Sweden's Sarah Sjostrom and other champions have used the same setup, which shows the habit spans strokes and distances rather than belonging to one event.
For amateur swimmers, the gain is far smaller than the gain from better technique or fitness. The double cap is a finishing touch for athletes already near their peak, not a shortcut for everyone else.
Latex versus silicone on their own
Latex caps are cheaper and grip well, but they wrinkle and can tear more easily. They also perish faster with chlorine exposure, so a latex cap used daily needs replacing sooner.
Silicone caps cost more and last longer, and they stay smoother through a race. Their drawback is that silicone can feel as if it is slowly slipping, especially over a long race, which is why swimmers pair it with a grippy latex layer beneath.
For swimmers curious about goggle care, the same logic applies: gear that stays put and stays smooth beats gear that needs adjusting mid-race.
Does every swimmer need two caps?
No. Most recreational swimmers need one cap that fits well, protects hair from chlorine, and keeps hair out of the face. Two caps add warmth, tightness and cost for a gain most casual swimmers will never notice.
Competitive swimmers with long hair get a second benefit from the inner cap: it holds hair flat before the goggles and outer cap go on. A single cap can let long hair shift during a dive, while the double layer locks it down.
Swimmers with short hair still use the trick, which shows hair control is only part of the story. Goggle security and drag reduction apply whatever the hair length.
[A plain swim cap, similar to the silicone outer layer of a double-cap setup.] Photograph: Wikimedia Commons contributor
Image Credits: Wikimedia Commons
FAQ
Do two caps keep water out of the ears?
Not fully. Swim caps reduce splashing around the ears but do not seal them, and swimmers who need ear protection use earplugs. The double cap is about goggles and drag, not waterproofing.
Can wearing two caps cause headaches?
A very tight pair can press on the head and feel uncomfortable, especially over a long session. Swimmers who feel pressure should try a larger outer cap or a thinner inner cap rather than forcing a small pair on.
Why not just wear one silicone cap?
Silicone alone can slip, while latex alone wrinkles and drags. Pairing them uses each material where it works best: latex for grip underneath, silicone for a smooth finish on top.
Is the double cap allowed in competition?
Yes. Wearing two caps is common at Olympic level and is not against the rules. Officials check caps for other reasons, such as advertising limits, not for the number of layers.
The bottom line
Swimmers wear two caps because the combination does two jobs better than either cap alone. Latex grips, silicone smooths, and the goggle straps sit locked between them.
The gain is small, but elite races are decided by hundredths of a second. For everyone else, one well-fitting cap does the job, and the double cap is a neat example of how much detail matters at the top of the sport.
Tags: swimming, Olympics, race gear
Rive News's research desk covers outdoor skills and everyday science explainers.
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