Swimming Kit Guide: How to Choose Goggles, Caps and Swim Gear

Most people buy their swimming kit in about four minutes. A pair of goggles off a supermarket shelf, whatever cap was nearest the till, and a swimsuit that looked about right. Then they wonder why the goggles flood on the second length, why the cap tears the first time it goes on, and why a costume that cost real money has gone baggy by October. Almost none of that is bad luck. It is the wrong kit, fitted the wrong way, and looked after badly. This guide fixes all three.

By the Swim Design Space Team  ·  August 2026  ·  12 min read

The swimming kit list, in order of importance

Swim shops are very good at selling you a bag full of things you will use twice. Here is what a swimmer at any level genuinely needs, ranked by how much difference it makes on the day.

A quick note on our own classes, because rules differ from school to school. At Swim Design Space we ask for a one-piece costume rather than a two-piece, a cap, and goggles, with long hair tied back before it goes under the cap. If you are booked in and want the full arrival routine, our guide on preparing for your first swim lesson covers the rest, and the swim school FAQs answer the admin questions.

How to choose swimming goggles that actually fit

Goggles are the one purchase where the label tells you almost nothing useful. Two pairs at the same price can behave completely differently on your face, because the thing that matters is the shape of your eye sockets and the width of your nose bridge. Neither is printed on the box.

There is a simple test that takes five seconds and works in any shop. Hold the goggles against your eyes with the strap hanging loose behind them. Press gently, then let go. A pair that fits will hold itself in place by suction for a moment or two before dropping. A pair that falls away instantly is too big for your face, and no amount of strap tension will save it.

That test works because the seal comes from the gasket, not the strap. The strap's only job is to stop the goggles moving. People get this backwards constantly, pull the strap tighter to stop a leak, and end up distorting the gasket so it seals even worse. If your goggles leave deep rings around your eyes after a swim, they are too tight. Loosen them until they are as slack as they can be while still holding water out.

Beyond fit, there are three decisions worth making deliberately:

• Gasket type. Soft silicone gaskets are the sensible default for lessons and general training. They are forgiving, comfortable over a long session, and easy to live with. Foam gaskets are cheaper but wear out faster. Rigid Swedish-style goggles with no gasket at all seal directly against the bone and are brilliant once you have learned to set them up, but they are not where anyone should start.
• Nose bridge. If water creeps in at the inner corners of your eyes, the bridge is almost always the culprit rather than the lens. An adjustable or interchangeable bridge solves more leaks than any other feature.
• Lens curve. Flat lenses are compact and low profile but flatten your sense of distance a little. Curved wraparound lenses widen what you can see out to the sides, which is worth having if you swim in a busy lane or head outdoors.

For a first proper pair in an indoor pool, a clear-lens training goggle with a silicone gasket is hard to beat. The FINIS Alliance in clear is the pair we hand people most often, and the full swim goggles range covers the smaller and wider face shapes around it.

Why goggles leak, and the fix that is not the strap

Leaking is the single most common complaint we hear poolside, and it is almost never the goggles being faulty. Work through this list in order and you will find the cause in under a minute.

• One trapped hair. A single strand across the gasket breaks the seal completely. Run a fingertip round the rim before you push off.
• The cap edge. If the bottom edge of your cap overlaps the goggle strap or gasket, it lifts the seal. Set the cap first, then put the goggles on over it, or tuck the strap under the cap deliberately rather than by accident.
• Sunscreen, moisturiser or facial oil. Any film on the skin stops silicone gripping. Rinse your face at the poolside shower before you put them on.
• The wrong nose bridge. Inner corner leaks nearly always mean the bridge is too wide. Try a size down before you blame anything else.
• A split strap worn wrong. The two halves are meant to sit at different heights on the back of the head, one above the crown and one below. Bunched together they let the goggles rock and leak on one side.
• Perished silicone. Gaskets go hard and slightly chalky with age. Once they will not hold the suction test any more, they are finished.

Two things people try that make it worse: soaking goggles in hot water to reshape them, which softens the silicone permanently, and cleaning the lenses with toothpaste, which is mildly abrasive and scratches them.

How to stop goggles fogging up

Fogging is condensation, nothing more exotic. Your face is warm, the pool is cooler, and the moisture coming off your skin and eyes settles on the inside of a cold lens as thousands of tiny droplets. New goggles do not fog because they leave the factory with a thin anti-fog treatment on the inner surface that makes water spread into an even sheet instead of beading. Once that layer is gone, the fog arrives.

Which brings us to the thing almost everyone does wrong. When goggles mist up mid-session, the instinct is to pull them off and wipe the inside with a thumb or a towel corner. That wipe removes some of the remaining anti-fog layer, so the next fog comes sooner, so you wipe again, and within a fortnight a decent pair is permanently hazy. If you take one thing from this article, make it this: never touch the inside of the lens.

What to do instead:

• Splash your face before you start. Bringing your skin temperature closer to the water's cuts the temperature gap that drives condensation in the first place.
• Dunk, do not wipe. When they mist mid-swim, dip the goggles in the pool and let the water sluice the inside. Then tip the water out and carry on.
• Put them on dry. Water sitting inside the lens before you start gives the fog a head start.
• Use anti-fog spray or wipes once the factory layer fades. These reapply a similar treatment and buy a pair several more months of clear vision. Follow the instructions rather than rinsing them straight off.
• Rinse in cold fresh water afterwards, then air dry. Chlorine left to dry on the lens eats the coating faster than anything else you will do to them.

The old tricks with saliva or baby shampoo do work, briefly. Both leave a film that stops droplets forming. The catch is that applying and rinsing them scrubs away whatever original coating survives, so you trade one clear session for a shorter overall life. Use them if you are stuck at the pool with nothing else, not as a routine.

Lens tints: which one for which pool

Tint is not decoration. It changes how much light reaches your eyes and how well you pick out the black line, the wall and the people around you. For the indoor pools most lessons happen in, more tint is usually worse.

One point worth clearing up: a dark or mirrored lens does not automatically protect your eyes from ultraviolet light. UV protection comes from a separate coating, and it is listed as a feature when a pair has it. For indoor swimming it barely matters. If you are heading outdoors or into open water it is worth checking, and our guide on preparing for open water as a pool swimmer goes further into the kit differences. For bright outdoor sessions the FINIS Lightning in blue mirror handles glare well, while the Bolt in smoke is the better one-pair-for-everything choice.

How long goggles last and how to stretch it

Goggles age by chlorine hours rather than by calendar months. Swimming twice a week, a well looked after pair should give you a year or more. Training six times a week, three to six months is realistic. Squeezing them into a damp bag and leaving them in a hot car will halve either figure.

Replace them when any of these show up. The gasket no longer holds the suction test. The lens stays cloudy even after a rinse and an anti-fog treatment, which means the coating has gone and no spray will bring it back. The strap has turned stiff or crusty and no longer springs back. There are scratches on the inside of the lens, which scatter light and cause more eye strain than the same scratches on the outside.

Direct sunlight, radiators and hot car boots are the three quiet killers. Heat degrades silicone, and once the gasket loses its softness it will never seal properly again. Rinse, shake dry, and keep them in their case rather than loose in the bag where a kickboard can land on them.

Swim caps: silicone, latex or lycra

Start with the honest bit. A swim cap will not keep your hair dry. It is not a seal, and water gets underneath within a length or two. What a cap does do is keep hair off your face, keep it out of the pool's filtration system, cut a little drag, and reduce how much contact your hair has with chlorinated water over an hour. Those are all worth having. Dry hair is not on the list.

The three materials behave quite differently:

• Silicone. Thicker, stretchier and far more durable. It slides on without grabbing hair, sits smoothly, holds a bit of warmth in a cool pool, and lasts years rather than months. It costs more up front and works out cheaper over time. This is the one we recommend for almost everyone.
• Latex. Thin, cheap and grippy. It holds hair flat well and breathes a little better in a warm pool, but it tears easily, tends to pull hair going on, and is out of the question for anyone with a latex allergy.
• Lycra or polyester mesh. The most comfortable to wear and the easiest to get on, which makes it popular with children and nervous adults. It does almost nothing for drag and lets water through freely, so treat it as a comfort item rather than performance kit.

If you have long or thick hair, the trick is preparation rather than a bigger cap. Tie it into a low bun or plait first so the volume sits at the back of the head rather than spread across the crown. Then stretch the cap wide with both hands, hook it over your forehead, and roll it back over the bun in one movement. Dragging a cap across the scalp is what pulls hair out. Long-hair and dome cut caps exist for genuinely thick hair and are worth the small extra cost.

Getting children to accept a cap is easier when it looks like something they want to wear. Our swim cap range includes the Mermaid silicone cap and the Animal Heads designs, both soft silicone, which removes most of the poolside argument.

Swimwear that survives a chlorinated pool

Here is why your favourite costume went baggy. Most high street swimwear is nylon blended with elastane, the fibre that gives it stretch. Elastane feels lovely and recovers beautifully, and chlorine breaks it down. Every session degrades the stretch fibres a little more, until the fabric sags, goes sheer at the seat, and stops holding its shape when wet. Heat, sunlight, body oils and sun cream all speed the process up.

The alternative is a costume built from polyester or PBT, or a blend of the two. These fibres shrug off chlorine, so the suit holds its shape through repeated pool use where a nylon and elastane version would already be finished. Testing puts the difference at roughly two to four times the working life, and in regular pool swimming that is the gap between replacing a costume every season and keeping it for years. Look for the words chlorine resistant, polyester or PBT on the label. Ignore any claim that a fabric lasts twenty times longer, which is marketing rather than measurement.

Fit is the other half of it. A costume should lie flat against you with no rippling or gaping at the neck and legs, and should still feel firm once it is wet. Gaps let water flush through as you swim, which is both cold and slow. If it leaves deep red marks or restricts your shoulders, it is a size too small. For lessons, a one-piece is what we ask for, and men are better served by close-fitting trunks or jammers than by baggy board shorts, which drag heavily and can catch on lane ropes. Two-piece suits and anything with loose ties are not suitable for a group class.

One habit worth adopting: buy two costumes and alternate them. Stretch fibres need a full day out of the water to recover their shape, and rotating a pair extends both of them well beyond what either would manage alone.

Training aids and what each one really does

Training aids are tools for isolating one part of your stroke so you can work on it without the rest getting in the way. Used well they speed progress up considerably. Bought in a bundle and used at random, they mostly just fill a bag.

• Kickboard. Parks your arms so your legs have to do the work. It builds kick strength and ankle flexibility and suits swimmers from the very first lesson. A kickboard is the one aid worth owning immediately.
• Pull buoy. Held between the thighs, it floats your legs so you can concentrate purely on the catch and pull. Useful once you have a stroke to refine, and easy to lean on as a crutch if you use it every session.
• Fins. They add propulsion and force your ankles to loosen up, which is the limiting factor for most adult kickers. Longer blades are gentler and more forgiving for developing swimmers. All-stroke training fins work across every stroke rather than just front crawl.
• Hand paddles. They increase the load on the pull and give you clear feedback on where your hand enters the water. Start small. Oversized paddles are a well known route to sore shoulders, and there is no benefit in jumping straight to the biggest pair. Strapless agility paddles fall off if your technique slips, which makes them self-correcting.
• Centre-mount snorkel. The most underrated item in the bag. It removes breathing from the equation entirely so you can focus on head position and body alignment, and it takes the repeated strain off your neck. A stability snorkel is genuinely useful from beginner level upwards, particularly if breathing is the part you find hardest.
• Hand floats. Small foam floats that give a nervous swimmer just enough support to relax and start moving. We use them constantly in early lessons, and the water confidence range is built around exactly this stage.

If you are buying one thing beyond the basics, make it a kickboard. If you are buying two, add the snorkel. The full training gear collection covers the rest as your stroke develops.

Kids' swimming kit: what changes

Children need the same five essentials, sized properly, plus a few things adults do not.

Goggles. Adult frames do not shrink to fit a small face, and a leaking pair is the fastest way to put a child off the water. Junior frames typically cover roughly six to fourteen, with dedicated infant styles below that. The fruit-scented kids' goggles are built for three to eight year olds and are usually the pair that finally sticks. The wider kids' swim gear range covers caps and floats in matching sizes.

Swim nappies. Any child who is not reliably toilet trained needs the double nappy system that UK pools ask for, which is a disposable or reusable swim nappy underneath and a snug neoprene nappy over the top. Ordinary nappies are not permitted anywhere, because they swell, sag and can burst. Swim nappies are designed to contain solids only. A leak can close a pool for hours, so it is worth getting right.

Warmth afterwards. Small bodies lose heat fast, and a shivering child remembers the cold rather than the swimming. A towelling poncho or changing robe gets them warm and dressed in half the time, and cuts out the changing room wrestling match entirely.

Ears. If your child is prone to ear trouble after swimming, our guide to preventing swimmer's ear in children covers what actually helps and what does not.

One rule for everyone, adults included: jewellery and watches come off before the water. Rings and studs catch, and lost items rarely come back from a pool drain. Contact lenses are the other one worth taking seriously. Pool water can carry an organism that causes a rare but very serious corneal infection, and lenses trap it against the eye. Wear prescription goggles if you can. If you must keep lenses in, seal them behind well-fitting goggles and throw the lenses away afterwards rather than reusing them.

Hair and skin after the pool

The most effective thing you can do for your hair takes fifteen seconds and happens before you swim. Soak it thoroughly under the poolside shower with clean fresh water. Hair absorbs water like a sponge, and a head of hair already full of tap water has far less capacity left for chlorinated pool water. Add a little leave-in conditioner underneath your cap and you have a second barrier over the cuticle.

Afterwards, rinse straight away rather than on the way home. Chlorine that dries into hair is harder to shift and does more damage sitting there. Ordinary shampoo is designed to lift oil, not to strip chemical residue, so regular swimmers are better off with a swimmer's or chelating shampoo once or twice a week alongside their usual one.

While we are here, the green hair myth. Chlorine is not what turns blonde hair green. Copper is, either from algaecide or from the pool's pipework, and it binds to the proteins in hair. Chlorine's role is indirect but real: it oxidises and roughens the hair surface, which gives copper more to hold onto. Pre-wetting, a cap and a proper rinse all reduce it.

Skin is simpler. Chlorinated water strips natural oils and leaves most people tight and dry. Shower properly, then moisturise while the skin is still slightly damp so you trap some of that water in rather than sealing chlorine underneath.

The two minute routine that doubles kit life

Nearly every piece of swimming kit dies the same way: chlorinated water left to dry on it, in a sealed bag, somewhere warm. The fix is the same for all of it.

• Rinse everything in cold fresh water before you leave the changing room. Cold, not hot, because heat damages both silicone and stretch fibres.
• Squeeze your costume gently. Never wring it, which is what breaks the fibres and creates permanent creases.
• Carry wet kit in a mesh bag so air can get to it, rather than sealed in plastic where it stays wet for hours.
• Hang everything to dry in the shade. Radiators, tumble dryers and direct sun all shorten the life of every item on this list.
• Store goggles in their case, dry, and away from anything heavy. Loose in a bag is how lenses get scratched.
• Hand wash costumes only, and rotate two so each gets a full day to recover.

Done consistently, that routine is worth more than spending twice as much on the kit in the first place.

Frequently asked questions

What do I need to take to a swimming lesson?

A close-fitting one-piece costume, goggles, a swim cap, a towel, poolside footwear and a water bottle. Long hair should be tied back before the cap goes on. Leave jewellery and watches at home or in the locker.

How tight should swimming goggles be?

As loose as they can be while still keeping water out. The seal comes from the gasket sitting correctly against your eye sockets, not from strap tension. If you are getting deep rings around your eyes or a headache afterwards, loosen them a notch or two.

Why do my goggles keep leaking?

In order of likelihood: a hair trapped under the gasket, the wrong nose bridge size, your cap edge sitting on the seal, sunscreen or moisturiser on your skin, or a split strap bunched together instead of sitting high and low. Tightening the strap is the one fix that usually makes it worse.

How do I stop my goggles fogging up?

Stop wiping the inside of the lenses, which is what strips the anti-fog layer. Splash your face before you get in, dunk and drain the goggles rather than wiping when they mist, rinse them in cold fresh water afterwards, and use an anti-fog spray once the original treatment fades.

Do swim caps keep your hair dry?

No. A cap is not a watertight seal and water gets underneath quickly. What it does is keep hair out of your face and out of the filters, reduce drag slightly, and limit how long your hair sits in chlorinated water. Wetting your hair first and using conditioner underneath protects it far more than the cap alone.

Silicone or latex swim cap: which is better?

Silicone for almost everyone. It is thicker, gentler on hair, warmer in a cool pool and lasts years rather than months. Latex is cheaper and thinner but tears easily, pulls hair, and is unsuitable for anyone with a latex allergy.

How long do swimming goggles last?

Roughly a year or more if you swim twice a week and rinse them after every session, or three to six months with daily training. Replace them when the gasket stops holding a light suction, the lens stays hazy after cleaning, or the strap turns stiff.

Is a chlorine-resistant swimsuit worth the extra cost?

If you swim regularly, yes. Polyester and PBT fabrics hold their shape through repeated pool use for around two to four times as long as nylon and elastane blends, so the higher price usually works out cheaper across a year.

What training gear should a beginner buy first?

A kickboard, then a centre-mount snorkel. The board builds your kick, which is where most adult beginners lose the most speed, and the snorkel lets you fix your body position without breathing getting in the way. Paddles and pull buoys are worth adding later once your stroke is settled.

Can my child wear a normal nappy in the pool?

No. UK pools require a swim nappy underneath and a snug neoprene nappy over the top. Ordinary nappies absorb water, swell and can split, and a leak can close a pool for several hours.

Kit gets you comfortable. Coaching gets you swimming. If you are in Gloucestershire and ready to start, we run adult lessons and children's lessons across Cheltenham, Gloucester and Blakeney. Book a class and bring the bag you have just packed properly.