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The best wetsuits for open-water swimming and triathlon, tried and tested

Whether you're starting to dabble in triathlon or simply fancy adding some open-water swimming to your cross-training routine, you're going to need a decent wetsuit to train in.

The best wetsuits offer a layer of insulation against the UK's infamously chilly waters, allowing you to swim in comfort for longer, while also providing some buoyancy and protection against floating debris.

Unlike 'normal' wetsuits, such as those you might use for surfing, wetsuits designed for wild swimming and triathlon are much stretchier and are extra flexible around the hips, knees and shoulders; this helps you to swim more freely. They are also more buoyant, to help you maintain a good body position in the water and therefore swim more efficiently.

While you can swim in a normal wetsuit, these are made from a different type of neoprene which is thicker and less comfortable and efficient to swim in. Wetsuits designed for triathlon and open-water swimming also have 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 swimming easier.

Our Runner’s World Lab team has been busy seeking out and testing some of the best wetsuits on the market for under £200. Here are their top six at a glance:

It’s vital you find a tight-fitting wetsuit to keep you warm in the water. Here’s why…

Wetsuits 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 is 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 patches, causing a deeply unpleasant sensation known as flushing. It really is all about the fit.

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. The Zone3 suits we tested had 4mm-thick buoyancy panels on the hips and legs. These 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, might find their legs are lifted too high by these panels. Triathletes are likely to prefer a neutral buoyancy, like the two Orca suits we trialled, which will allow the legs to rise and fall in the water more naturally.

As a rule of thumb for swimming in Britain, a 3mm torso is a good fit for tepid summer waters, 4mm will keep you warm in spring and autumn and 5mm will help tackle the cold 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, however, this is something you shouldn't need to worry about, as most major brands will have taken this into account when manufacturing their wetsuits.

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 their performance, letting us know if they kept them warm and were flexible enough for a race-winning front crawl.

The best models fitted like a glove and offered plenty of protection from the cold, allowing the testing team to stay in the water for longer. They were stretchy enough to let us swim freely, and they didn’t dig in or chafe.

The 'Editor's picks' wetsuits below are those that have been tested and rated by our editors and contributors who 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, and are better suited to more competitive swimmers and experienced triathletes.

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 limbs, 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.

Material: Yamamoto neoprene, Infinity skin high-end lining

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 give a great fit, particularly for taller testers. It also allowed them to move with 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 delivered a classy performance.

Key specifications Material: Speedflo neoprene (70%) and smoothskin neoprene (30%)

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.

Material: Yamamoto 39 neoprene, Infinity Skin high-end lining

Fits: Men’s and women's

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.

Material: Neoprene (80%) and polyamide/nylon (20%)

Thicker than most wetsuits 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. Decathlon advises that, following advice from previous customers, you should buy a size up.

Material: Foam rubber, chloroplene and neoprene lining polyester

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 proved 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 makes it a solid travel companion.

Material: Super stretch smoothskin neoprene

That much for a wetsuit, we hear you say? Expensive, yes, but it's Roka's fastest and most efficient wetsuit. Hence why you'll find Ironman athlete and 70.3 world champion Lucy-Charles Barclay swimming in this suit – and she holds multiple swim-course records!

So, what do you get for your money? Where most suits use only one or two different liners for the exoskeleton, this uses seven, making the suit stiffer which enhances swimming efficiency. In this latest iteration of the Maverick, Roka also invented a new taping technique to connect – and maximise power transfer between – your hips and shoulders. It also features Roka's patented arms-up technology designed to eliminate shoulder restriction, and features strategically placed panels in the legs, core and hips to enhance buoyancy.

The Maverick feels genuinely feels like a second skin – the fit is tight without feeling restrictive – and we found it helped us to feel much more stable, and streamlined, in the water. It provides exceptional buoyancy around the core, hips and legs, which is great if you struggle with sinking legs, however those who have good natural buoyancy may find this feels a little unnatural and distracting.

With so much tech packed into this suit to make you swim faster, this is a wetsuit for competitive triathletes looking for maximum gains in the water.

Material: Yamamoto neoprene, SCS hydrophobic nano coating

Colours: Black/Spark, Black/Torch

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 by the suit. 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 we found it very comfortable during long stints training in open water. The fit is also true to size.

This entry-level wetsuit is ideal for beginners looking to dip their toe in triathlon for the first time. The Yamamoto 39 Cell neoprene varies in thickness throughout the body of the wetsuit, in order to improve buoyancy and prevent sinking legs.

There's a zip panel down the back made of stretchy non-laminated neoprene, which not only makes putting the wetsuit on easier but helps to improve movement in the shoulders when swimming. In the water, it feels fast and snappy, which could possibly be attributed to the rollbar tech which prevents buoyancy on the perimeter of wetsuit, to make side-to-side rotation quicker.

'I'm a big fan of this suit,' said our deputy digital editor Jenny Bozon, 'it's roomier in the upper and around the neck than many wetsuits I've tried before, which makes it comfier to swim in, as your stroke isn't inhibited and it doesn't feel restrictive around the chest.'

Colours: Back/Sunset Ombre, Black/Blue Ombre, Black/Silver Shadow

Previously known as the Orca S7 and renamed the Athlex Float as part of a re-brand by Orca this spring, this high-elasticity wetsuit is designed to give swimmers who need it extra buoyancy in the water. It's incredibly comfortable to swim in and feels in no way restrictive, thanks to the thinner layer of neoprene in the upper body, which allows for complete freedom of movement around the shoulders, while in the legs you've got a thicker 4.5mm of neoprene, which helps to keep your legs elevated. We found it true to size and super easy to slide on, which makes a nice change to less flexible wetsuits, which can be a bit of a fight to pull over your trunks or swimsuit.

A great choice for newer triathletes, or those who are working on their swim technique and require a little assistance with their body positioning.

Material: Yamamoto 39 neoprene, Infinity Skin 2 lining

Colours: Red/Black, Grey/Black

Roka say the Comp II is the 'fastest, most natural-feeling entry-level wetsuit on the market'. It has been patterned with the arms above the head, and this 'arms up' construction offers noticeable freedom of movement in the shoulders – in fact, the tech almost coaxes you to lift up your arms.

There's increased buoyancy down the centre of the suit, which is designed to optimise body rotation, and a graduated profile which helps to keep the legs higher in the water.

The neck panel is seamless and our tester, who is often prone to chafing while wearing a wetsuit, experienced no rubbing whatsoever. He also loved the quick release panels at the ankle which made the suit easy to pull off, and found it fit true to size.

Packed with tech but more affordable than some of Roka's higher-end offerings, it's a great choice for both entry-level and intermediate swimmers and triathletes.

Colours: Blue/Back, Purple/Black