Triathlon wetsuit: fit, thickness, rules and hire in the UK

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A triathlon wetsuit is a thin, flexible neoprene suit made for swimming in open water. It keeps you warmer, lifts your legs and lets your shoulders move freely. Choose one on fit first, then on how thick the panels are. In UK races, British Triathlon rules decide when a wetsuit is compulsory and when it is banned.

We have not tested any wetsuit. This page explains what to look for, what each brand states about its models and where the rules come from. Prices were checked on 6 October 2026 and change often, so check the shop before you buy.

Triathlon wetsuit or surf wetsuit?

A surf wetsuit is made to keep you warm while you sit on a board and paddle in short bursts. It is usually built to resist wear, and the arms and shoulders are not designed for a long front crawl stroke. On a long swim, many people find a surf suit tiring on the shoulders.

A triathlon wetsuit is made for swimming. Brands use thinner neoprene on the arms and shoulders for reach, thicker panels on the body and legs for lift, and a smooth outer coating to move through the water. Zone3, for example, states a Speedflo coating on its Glide model. Triathlon suits also tend to come off faster in T1 (the first transition, from swim to bike).

A surf wetsuit is fine for a one-off first race. If you will swim open water through the season, a swimming wetsuit is worth hiring or buying.

Fit and sizing

Fit matters more than any feature. A good triathlon wetsuit fit looks like this:

• Snug on the body, with no folds or air pockets at the lower back, under the arms or at the crotch.
• The crotch sits high. If it hangs low, the shoulders will pull when you reach forward.
• You can lift your arms over your head and take a full breath without the chest feeling clamped.
• The neck seals without rubbing. A tight collar on land usually feels better in the water, but a sore neck after a long swim means it is too tight or needs anti-chafe balm.

Use the brand's own size chart. Size ranges differ: Zone3 lists sizes such as S, SM, M, ML, L, XL and XXL on its Active-Flex, and adds tall sizes (ST, MT) on several other models. The Orca Athlex Flex on the retailer page we read used numbered sizes 4 to 11 plus MT. If you are between sizes, try both if you can.

Thickness and buoyancy, as brands state them

Neoprene thickness is given in millimetres and is usually different across the suit. Zone3 describes its Active-Flex with thicker panels on the body and thinner panels on the arms, and other models give a range of thicknesses:

• Zone3 Active-Flex: 3mm on the chest, core and upper legs, 2mm on the arms and lower sections.
• Zone3 Advance: 1.5mm to 4mm.
• Zone3 Vision: mentions 5mm Aerodome panels; the overall thickness is not stated.
• Orca Athlex Flex: described as having high upper-body elasticity and neutral buoyancy.

More buoyancy lifts the hips and legs, which helps swimmers whose legs sink. Strong swimmers with a good body position may prefer a suit described as more neutral. If you are new to open water, a suit with clear buoyancy panels on the legs and core is a sensible place to start.

Listed triathlon wetsuit models and prices

All are men's models, as listed on 6 October 2026. Prices change, and some sizes were sold out on the day.

For a first season, the Glide is the model Zone3 itself calls entry level, and the Active-Flex is the lowest listed price. The higher-priced suits add more varied panel thickness and named neoprene grades. We could not verify HUUB prices in pounds, so HUUB models are not in the table.

See triathlon wetsuits at Sigma Sports

British Triathlon wetsuit rules

In races run under British Triathlon's Competition Rules 2026, rule 4.2 sets the water temperatures. Age is your age on 31 December.

The rules recommend that novices and age-groupers (non-elite racers, grouped by age) up to 59 wear a wetsuit up to 22 °C. Under rule 4.4 there is no open water swim in competition below 11 °C, and the maximum swim distance is shortened in cold water: 1000 m at 13 °C, 600 m at 12 °C and 300 m at 11 °C. The water temperature is taken one hour before the start. Races outside Great Britain run under World Triathlon rules follow those instead. See our guide to British Triathlon rules for drafting, distances and race licences.

Hire or buy?

Hiring makes sense for your first season, while you find out whether you like open water and which fit suits you.

• Zone3 season hire: the men's Glide season rental was listed at £69 for the 2026 season (until 30 September 2026), with a £50 refundable deposit at checkout and a hire agreement to accept. Zone3 says 2027 season rentals dispatch from early 2027 (checked 6 October 2026).
• Tri Wetsuit Hire: listed on the Royal Windsor Triathlon website, with Orca, HUUB, Yonda, Blue Seventy and Aquasphere suits, hire from one week to a season and "no deposit". The page did not state a price.
• At the venue: Love Open Water's Royal Docks page lists wetsuit hire at £10 per session. West Reservoir Centre does not hire wetsuits. See open water swimming in London for venue details.

Buy when you know you will swim regularly and you have found a size that fits well.

Hire a Zone3 wetsuit for the season

Wetsuit care

• Rinse inside and out in cool fresh water after every swim.
• Dry it inside out, away from direct sun and heat, then turn it the right way to finish.
• Put it on with care: pull from the inside using the pads of your fingers, not your nails. Cotton gloves help.
• Store it flat or folded over a wide hanger, never on a thin wire hanger.
• Keep it away from hot water, petroleum-based lubricants and sharp velcro.

Ready for the water? Read our tow float and goggles guide, check the full triathlon kit list, and book a session at West Reservoir.

Frequently asked questions