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13 best wetsuits for open water swimming and triathlons, with big summer savings
Take the plunge or dip your toe with these tested suits
Tested by Yanar AlkayatFormer Fitness Group Testing ManagerTested by Jodie MorrishHealth and Fitness Tester
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Fancy dipping your toe into triathlons or adding open-water swimming to your cross-training routine? Then you're probably going to need one of our expert-tested wetsuits to train in.
The best wetsuits offer a layer of insulation against Britain's infamously chilly waters, allowing you to swim in comfort for longer, while also providing some buoyancy and protection against any floating debris.
Is a swimming wetsuit different?
Unlike 'normal' wetsuits, such as those you may use for surfing, wetsuits designed for wild swimming and triathlons are stretchier and extra flexible around the hips, knees and shoulders to help you swim more freely.
They are also more buoyant, helping you maintain the best body position in the water and therefore swim more efficiently.
Can you swim in a normal wetsuit?
While you can swim in a normal wetsuit, they are made from a different type of neoprene that's thicker and less comfortable and efficient to swim in.
Wetsuits designed for triathlon and open-water swimming also have a Super Composite Skin (SCS) coating, which is smooth and helps you to be more streamlined in the water.
Opting for an open-water specific swimming wetsuit will ensure you don't overheat and will make getting in those strokes easier.
How does a wetsuit work?
It’s vital you find a tight-fitting wetsuit because they keep you warm by acting as a second skin. When you submerge yourself in the sea (or your lake, pond or river of choice), a thin layer of water gets trapped between your skin and the neoprene. This is quickly warmed by your body heat, creating an insulating barrier between you and the icy currents.
But, be warned: cold water will rush into any baggy areas, causing a deeply unpleasant sensation known as flushing. It really is all about the fit.
What should I look for in a wetsuit?
The best wetsuit for you will depend on what you want to use it for, as competitive triathletes will have more demands than casual paddlers. That said, there are some common key factors to consider.
Fit: Quite simply, your wetsuit will be useless if it doesn’t fit snugly – loose areas around the joints are an open invitation for flushing.
Flexibility: Wetsuits for open water swimming should have plenty of stretch around the knees, hips and shoulders. If you can’t raise your arm past your ear, then front crawl is a no-go.
Thickness: Wetsuits come in varying thicknesses for use in different seasons. This is usually displayed as two numbers separated by a slash or colon.
For example, 3:2 suits are among the most popular in the UK. The first figure represents the thickness of the torso (in millimetres) and the second, the thickness of the limbs (also in millimetres). The arms and legs tend to be thinner to allow for greater flexibility.
Buoyancy: Thanks to their thick neoprene build, wetsuits will provide a bit of extra buoyancy. But there’s a touch more to it than that. Wetsuits with thick buoyancy panels on the hips and legs are great for beginners, as they will lift your lower body in the water, placing you in a more powerful position for front crawl.
Stronger, more experienced swimmers, however, may find their legs are lifted too high by these panels. Triathletes are likely to prefer a neutral buoyancy that will allow the legs to rise and fall in the water more naturally.
What thickness wetsuit is best for swimming?
For swimming in Britain, a 2.5mm torso is best suited to tepid summer waters, 3.5 or 4mm will keep you cosy in spring and autumn, and 5mm will help keep the cold at bay in winter (providing there’s not a dusting of snow on the beach).
British Triathlon Federation race rules state that wetsuits must not exceed 5mm in thickness, but don't worry too much about this – most major brands will have taken it into account when manufacturing their wetsuits.
How we test
Our Runner’s World Lab testers took a range of wetsuits out for a series of swims, submerging themselves in ponds, lakes and the sea in the name of research.
They then fed back on each wetsuit's performance, letting us know if they kept them warm and proved flexible enough for a race-winning front crawl.
The best models fitted like a glove and offered plenty of protection from the cold, allowing our testers to stay in the water for longer. They were stretchy enough to let them swim freely, and they didn’t dig in or chafe.
The winning wetsuits that earned our team's seal of approval are stamped with the Runner's World Expert Tested logo.
The remaining suits below have been tested and rated by our editors and contributors, all of whom swim in open water regularly and compete in triathlons. Some of these wetsuits are a little more technical – and therefore more expensive – than the wetsuits we tested in the lab, making them better suited to more competitive swimmers and experienced triathletes.
Best wetsuits for wild swimming
Openwater Core Hi-Vis Wetsuit
Openwater Core Hi-Vis Wetsuit
Now we’ve told you what makes a good wetsuit, it’s time to give you an example. In true Blue Peter fashion: here’s one Orca made earlier. This hi-vis suit’s USP is its bright orange panels, which reassured our testers as it made them easier to spot from the shore.
It also nailed the basics. The stretchy Yamamoto neoprene was easy to slip in and out of while still providing that vital tight fit, and our team’s shoulders were able to move freely, whatever their stroke. The relatively thin fabric still kept them comfortable, and there was no digging in or chafing.
Key specs
| Material | Yamamoto neoprene, Infinity skin high-end lining |
|---|---|
| Thickness | 2:5:2 |
| Colours | Black/orange |
| Fit | Men and women |
Zone3 Azure 2.0 Wetsuit
Zone3 Azure 2.0 Wetsuit
This slightly thicker suit is sure to keep you warm in autumn waters, yet the 4mm-neoprene is still lightweight and flexible — ideal for speedy swims. The buoyancy panels in the legs and hips were helpful, too, moving newer swimmers into a better position in the water.
Our team praised the sporty design and said the stretchy material helped create a great fit, particularly for taller testers. It also allowed them a full range of motion. They found the zip tricky to do up without a helping hand, however, and the arm holes a bit tight to squeeze into. But, once on, it definitely delivered.
Key specs
| Material | Speedflo neoprene, smoothskin neoprene |
|---|---|
| Thickness | 4:2 |
| Colours | Black/neon blue |
| Fit | Men and women |
Openwater Core TRN
Openwater Core TRN
The neutral buoyancy of this suit makes it a great fit for stronger swimmers looking to make the leap from pool to pond or sea. It won’t push your lower half up in the water, so it’s down to you to power your way to parallel for a powerful front crawl.
Testers said they could swim in complete comfort, thanks to the suit’s tight fit and the absence of any chafing or digging in. They also reported that it was slightly warmer than our winning Orca, with the neoprene made to be half-a-millimetre thicker around the chest and abdominals. There was a little bit of seeping around the neck, but that was the only chink in the TRN’s armour.
Key specs
| Material | Yamamoto 39 neoprene, Infinity Skin high-end lining |
|---|---|
| Thickness | 3:2 |
| Colours | Black and orange |
| Fit | Men and women |
Nabaiji Decathlon Neoprene Open-Water Swimming Wetsuit 4/2mm
Nabaiji Decathlon Neoprene Open-Water Swimming Wetsuit 4/2mm
Thicker than most suits we trialled, this offering from Nabaiji made sure our testers didn’t freeze in some unforgiving spring waters. Instead, they were kept at a pleasant temperature throughout their swimming sessions as the neoprene effectively trapped a warm layer of water.
Some testers said they felt a little bit of flushing around the neck and groin, but most were well protected from the cold. Following feedback from previous customers, Decathlon advises buying a size up.
Key specs
| Material | Foam rubber, chloroplene and neoprene lining polyester |
|---|---|
| Thickness | 4:2 |
| Colours | Black |
| Fit | Men and women |
Orca Athlex Float Triathlon Wetsuit
Orca Athlex Float Triathlon Wetsuit
Previously known as the Orca S7 and renamed the Athlex Float as part of a rebrand by Orca this spring, this high-elasticity suit is designed to give swimmers who need it extra buoyancy in the water.
Our testers described it as, ‘a total joy to swim in'. It was incredibly comfortable and felt in no way restrictive, thanks to the thinner layer of neoprene in the upper body. In the legs, you’ve got a thicker 4.5mm of neoprene to keep your legs elevated and our swimmers confirmed it helped them stay afloat.
It’s a cinch to slide on and off. The back zip is easy to reach and it comes with gloves to prevent you snagging your nails on the neoprene – super handy for speedy triathlon changeovers. The snug fit and absence of bulging meant no flushing was reported and it dried in a flash, so you can use it daily.
A few panellists did get a little chilly during longer swims on cold days, but the suit is designed for use in warmer temps so that’s hardly a deal-breaker. A great choice for newer triathletes.
Key specs
| Material | Yamamoto 39 neoprene, Infinity Skin 2 lining |
|---|---|
| Thickness | 4.5mm neoprene in the legs |
| Colours | Red/black, Grey/black |
| Fit | Men and women |
Zone3 Women’s Aspect 'Breaststroke' Wetsuit
Zone3 Women’s Aspect 'Breaststroke' Wetsuit
The second Zone3 offering in this round-up, this suit has been specifically designed for swimmers who are partial to breaststroke (if you hadn’t guessed by the name). It features high-stretch panels around the shoulders and groin for totally unrestricted movement and has minimal buoyancy in the lower legs for the perfect breaststroke position.
Our testers barely noticed they had it on thanks to the comfortable, flexible fit and they didn’t experience any digging in, chafing or gaping. ‘It’s the most comfortable wetsuit I’ve ever worn!’ said one satisfied swimmer. It kept everyone warm during long stints in even the chilliest of waters and testers loved the pops of colour on the arms for style and safety.
Any downsides? The cuffs are rather tight so you won’t be able to wear a fitness tracker under the suit, and you may need a helping hand getting it on. That wouldn’t stop our panel reaching for it again, though.
Key specs
| Material | Neoprene |
|---|---|
| Thickness | N/A |
| Fit | Women's |
dhb Hydron Wetsuit 2.0
This wetsuit is popular with entry-level athletes, dhb says, as it offers the sought-after triad of flexibility, buoyancy and value for money. In testing, we found it delivered on all three fronts. The neoprene gave our team the second skin fit they were looking for and proved pliable enough to let their arms move unhindered. It also kept them at a comfortable temperature in spring waters while pushing the pace.
The chunky back zip felt cheap and the chest felt too tight for some, but these were minor qualms, particularly given the very reasonable price tag.
Key specs
| Material | Neoprene, polyamide/nylon |
|---|---|
| Thickness | 3:2 |
| Colours | Black and white |
| Fit | Men and women |
Orca Vitalis Shorty Women's Openwater Wetsuit
Orca Vitalis Shorty Women's Openwater Wetsuit
This shorty wetsuit is ideal for summer when you want your arms and legs free but some extra warmth around the torso wouldn’t go amiss. It was a total joy to wear, according to our testers, who said they barely noticed they had it on as they moved through the water.
The fabric was thick enough to keep goosebumps at bay and the snug, figure-hugging fit meant there was no excess material to slow them down. Still, they enjoyed unrestricted movement around the arms and shoulders thanks to Orca’s clever infinity skin 2 technology, and there was no irritating chafing around the neck. Post-swim, the suit was a cinch to slip out of solo thanks to the generous zipper and it dried off quickly, too.
Everyone loved the bursts of colour beneath the arms and thought the design was extremely flattering. Look to one of our other options, like this Decathlon number, if you’re heading out in cold conditions, but if you just want some extra protection for your summertime swims or water sports sessions, this is your guy.
Shop now - women's
Key specs
| Material | Yamamoto 38 neoprene |
|---|---|
| Thickness | 2:3 |
| Fit | Women's |
Sola Open Water Swimming Wetsuit
Sola Open Water Swimming Wetsuit
A wetsuit can be a bulky addition to your backpack if you’ve got your sights set on a coastal staycation. Luckily, this Sola suit offers a partial solution to this problem, with testers finding it easier to fold up and pop in a bag than others on trial.
It’s a good thickness for a summer suit, but will still do a reliable job in late-spring and early-autumn waters. The smoothskin neoprene is a little difficult to grasp, making it a faff to take off, and our range of motion felt slightly limited. But its lightweight design and streamlined fit make it a solid travel companion.
Key specs
| Material | Super stretch smoothskin neoprene |
|---|---|
| Thickness | 3:2 |
| Colours | Black |
| Fit | Unisex |
Nabaiji Decathlon Nabaiji Men’s Open Water Swimming Wetsuit 2/2mm
Nabaiji Decathlon Nabaiji Men’s Open Water Swimming Wetsuit 2/2mm
For fair-weather water babies who don’t want to spend over the odds on a techy suit, meet your new swimming companion.
It’s a great all-rounder, according to our testers, who found it was easy to pull on over their trunks and appreciated the decent range of motion it afforded them – it was flexible enough for most strokes, including breaststroke and butterfly. They rated the fit around the glutes, torso and chest but some found the wetsuit a bit too snug beneath the arms, making it tricky to run in. As such, we wouldn't recommend it for triathletes, but it’ll do the job nicely for all your casual swimming adventures.
Despite the modest price tag, testers were impressed with the overall quality of the suit, with many saying it had an expensive feel. They found it trapped heat well and offered enough insulation for the milder months. With a 2.5mm torso, however, it won’t keep you toasty enough during the freezing British winters.
Key specs
| Material | Rubber, polyamide, elastane, polyurethane |
|---|---|
| Thickness | 2.5:2 |
| Fit | Men's |
Mountain Warehouse Mountain Warehouse Women’s Full Wetsuit
Mountain Warehouse Mountain Warehouse Women’s Full Wetsuit
Another beginner-friendly option, this simple Mountain Warehouse style ticked several boxes for our testers. Unlike more techy suits that can be a bit of a fight to pull on, they had no issue slipping into this one – the fabric proved lightweight and supple, and the smooth easy-glide zip panel worked a treat. In the water, the stretchy neoprene allowed their arms and legs to move freely, and it successfully kept the cold at bay, even for short swims in near-zero temperatures.
With built-in UV protection of up to UPF 50+, it’s a great one to chuck in your suitcase for beach holidays. Plus, it has a rubber panel on the chest and tough, durable knee pads – useful additions if surfing, paddleboarding or river swimming are on the agenda. What’s more, it dried within 24 hours, so you can use it day after day.
Serious swimmers, look to one of our other options – panellists felt this one wasn’t high-tech enough for lengthy sessions – but it’s absolutely ideal for recreational swimming and water sports.
Key specs
| Material | Neoprene, polyester |
|---|---|
| Thickness | 2.5:2 |
| Fit | Women's |
Orca Vitalis Breast Stroke Women Open Water Wetsuit
Orca Vitalis Breast Stroke Women Open Water Wetsuit
Like the Zone3 offering above, this good-looking style from the experts at Orca has been designed with breaststroke in mind. Unlike standard wetties, which can be on the stiff side, the Yamomoto neoprene is supremely stretchy and varies in thickness across the suit, allowing for total freedom of movement and a more powerful breaststroke position. Sure enough, our testers said thrashing through the stroke was a breeze, and it worked just as well for front crawl and freestyle, too.
Everyone loved the secure, silhouette-hugging fit and said it provided plenty of warmth, helping them stay in the water for longer. Despite the close-fitting design, it was easy enough to peel off after a swim, and the extra-long zipper meant they didn’t need a pal to help them shimmy out of it.
Panellists did report a strange smell when the suit was wet, and the sizing proved hit and miss – make sure you take your measurement before you buy – but those were our only gripes. All in all, an excellent choice for breaststroke aficionados.
Key specs
| Material | Yamamoto 38 neoprene |
|---|---|
| Thickness | 2:2.5 |
| Fit | Women's |
A new and updated version of the much-loved Orca Sonar, the Athlex Flow is a favourite among intermediate triathletes. Our tester, who wore the suit while training for – and competing in – an Ironman-distance triathlon was impressed by the amount shoulder flexibility offered. He also enjoyed how the suit, which is made of flexible Yamamoto neoprene, aided buoyancy, allowing him to adopt a more streamlined body position in the water.
This wetsuit has a laser-cut design and is soft to the touch, and our tester found it very comfortable during long stints training in open water. The fit is also true to size.
Key specs
| Material | Yamamoto neoprene |
|---|---|
| Fit | Men and women |
Yanar was our former Fitness Group Testing Manager. She managed health and fitness product testing across all the magazines, overseeing all testing processes and ensuring our lab and panel tests are conducted to the highest standards. Yanar spent 15 years as a health and wellness content editor and writer for national titles such as Runner’s World, Men’s Health and Women’s Health. Yanar is a Level 3 qualified PT, trained yoga teacher and a registered yoga therapist. She has been into fitness and wellness her whole life. After many years running races and marathons, she now trains and competes in CrossFit and Olympic lifting. She passionately advocates strength training for women to build a stronger mind and body for life.
Jodie is our Health and Fitness product tester. She runs tests on a wide variety of products, including gym leggings, walking boots, fitness trackers and more. Jodie has managed the testing for 577 products to date, including working with over 600 panellists.
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