For those brave enough to swim outdoors in winter, there have, until recently, been two options: wear an ordinary swimsuit and feel the thrill/horror of cold water on your skin for a few minutes; or pull on a wetsuit and stay in for longer, but without the endorphin high.
But there is now a third way: a cold-water swimsuit, made from thermal fabric to keep your core warmer for longer and lengthen your time in the water. A wetsuit may seem the obvious choice for winter swimming, but many open-water wetsuits won’t offer much warmth in water below 10C, and the effort of putting one on at this time of year when swims are short often isn’t worth it (see more detail below). But is a cold-water swimsuit any different from a standard suit, and are they worth buying? I tested seven of the best to find out.
At a glance
Why you should trust me
I’m an experienced, year-round outdoor swimmer, teacher, guide and lifeguard, and the author of How to Wild Swim: What to Know Before Taking the Plunge. I frequently enjoy dips in rivers, lakes, ponds and the sea, as well as long-distance swims in the warmer seasons. I also have a decade of experience testing swim kit for outdoor publications.
I have first-hand experience of poor-fitting swimwear, with the chafing scars to prove it. This has given me the firm belief that the best thing to wear when swimming is something comfortable that supports your body and is suitable for the type of swim you want to do. Whether that’s a string bikini or a hooded wetsuit, it’s all fine as long as you are safe and happy.
How I tested
I took the swimsuits to the same body of water – my local lake, QuaySwim, in Surrey. I ensured the water and air temperature were the same each time – the former a cool 8C, the latter 6C. I made sure I felt fit, well and warm, and that I was swimming in similar weather conditions.
But many factors affect whether you feel cold while swimming outdoors – from the level of sunshine, to how much you’ve slept or eaten – so testing couldn’t be an exact science. I experimented with body and skin thermometers, but it was pointless; if my body temperature had dropped, I would be entering hypothermia.
I researched suits specifically designed or marketed for cold water, with a mix of brands, materials, sleeve length, neckline and price. While long sleeves can psychologically make you feel warmer, having more wet fabric against the skin can actually make you feel colder. Long sleeves work well when the fabric is snug against the skin, and is thicker or has a technical element to it.
After testing, I donated these suits to the Every Body Outdoors kit pool, a community campaigning for clothing, gear and representation for larger bodies in the outdoors, which I previously wrote about for the Guardian.
The best cold-water swimsuits for women
Best overall cold-water swimsuit:
Zoggs Brave crossback
When Zoggs designed silver-lined suits a couple of winters ago, I was convinced it was a marketing stunt. The lining is a bit like a first aid foil blanket designed to retain body heat: Zoggs claims it helps retain body heat for 60% longer than normal swimwear.
Whenever I plunge into cold water my skin turns bright pink due to increased blood flow and dilating blood vessels – it’s this that creates that psychological high. If I wear neoprene gloves during my swim, I see a significant difference in the colour of the skin on my hands compared with my arms. This suit maximises exposed skin with a crossback design, while still keeping your core warm and chest covered with its high neckline.
Why we love it
I felt warmer, and my skin under the suit was visibly warmer, not red like the skin exposed directly to the cold. My recovery was quicker after I got out, too. The uplifting neon animal print design is perfect for visibility in the grey, low light of winter. I also loved that you can remove the padded cups in the bust area.
It’s a shame that … Zoggs hasn’t continued to develop the concept into a long-sleeve suit.
Suitable for: outdoor dips and longer swims
Material: Ecofeel fabric: 79% recycled micro polyamide, 21% elastane made from recycled plastic waste
Sizing: UK8-26
£65 at Zoggs
£64.99 at Swim the Lakes
Best sustainable cold-water swimsuit:
Finisterre Nieuwland 2mm Yulex long-sleeve
Finisterre is an expert in keeping water lovers warm. It’s predominately a surf brand, with years of experience designing wetsuits that offer warmth, flexibility and durability – and this suit is no different. Made from Yulex natural rubber, a plant-based alternative to neoprene, it operates like a wetsuit by allowing water into the suit, which then warms up against your skin to keep you insulated. But the swimsuit design enables you to still enjoy the elements on your bare skin.
Long sleeves, 2mm fabric and a high neckline keep the upper body and core warmer for longer, and the clever seam placement in the shoulders ensures you get a full range of movement for some serious swimming. If you feel the cold, this suit is ideal: it made a significant difference to my swim, allowing me to spend 20 minutes more in the water than usual at 8C. It wouldn’t be allowed for swimming the Channel or at winter swim events, because of the Yulex fabric and long-sleeve design, but it’s a winner if you want to spend as much time as possible in the water over winter. Finisterre offers similar Yulex products without sleeves and as separates. Everything is delivered in biodegradable packaging, and the brand offers repairs, pre-loved products and the option to trade in old gear.
Why we love it
As well as keeping you warm, it gives you more buoyancy in the water like a wetsuit, lifting you into a prime position for swimming. Finisterre has also recently extended its size range to a UK22, and there’s a rental option if you want to try before you buy.
It’s a shame that … it’s a little tricky to take off once wet. Bending and flexing to get the suit off solo was a workout, but swimming with a pal will solve that issue.
Suitable for: longer swims, paddle boarding, surfing and cool dips
Material: 85% Yulex, 15% synthetic rubber
Sizing: UK6-22
£150 at Finisterre
Best for simplicity:
Zone3 OWS Ti+ thermal high neck costume
This classic high-neck suit in sleek black will be popular with traditional swimmers who like simplicity. It has a titanium lining in the front and back panels, which gives thermal benefits to your core. Much like the Zoggs silver-lined suits, this left my arms and legs exposed but kept my core warmer for a little longer.
I liked the high neck, which gave coverage against the wind across the neckline and upper back. It also meant less drag when swimming. The lining made a difference, too, and it certainly felt warmer compared with Zone3’s other high-neck suits. The leg cut and body length are ideal, but coverage across the bust was a little lacking, so it didn’t feel as supportive as other suits. An extra inch of fabric could have made all the difference. Those with smaller busts are unlikely to have these issues.
Why we love it
The shiny, slick material is stylish and practical and the fabric is designed to retain shape after multiple uses. I really stretched and tugged at it, and also put it through a machine wash, and was impressed that it did indeed retain its snug fit. The long zip is ideal for quick changing after a cool dip.
It’s a shame that … it doesn’t come in more colours. A lot of Zone3 swimwear is navy, grey and black.
Suitable for: outdoor dips, short swims and wearing under a wetsuit
Material: body 79% polyamide, 21% elastane; lining 87% polyester, 7.8% polyester ti, 5.2% spandex
Sizing: UK8-20
From £65 at Amazon
£75 at Zone3
More stock will arrive at Zone3 in early March
The best of the rest
Chilly Swim Shark Bite
Best for: thickness
Chilly Swim is a small business offering just three designs, all made from limestone neoprene. Limestone neoprene – a non-petroleum-based neoprene – is often touted as an “eco-friendly” alternative to petroleum-based neoprene. However, as limestone is non-renewable and sourced from mines with a detrimental environmental impact, many still feel it isn’t much better.
But I’ve included this Jaws-inspired swimsuit in my roundup because it hooked me in with its performance in the water, and it’s still more environmentally friendly than traditional neoprene, with its smaller production carbon footprint. This suit is 2mm thick – open-water wetsuits are usually between 3mm and 5mm thick – and allows ease of movement, with exposed arms and legs, while keeping your body warm. It’s warmer than a standard Lycra swimsuit, and I liked the lining against the skin, as well as how sucked-in and supportive it felt. It added warmth to my core, but I could still feel the zing of cool water on my skin.
Those thermal benefits were, however, cancelled out in front crawl, with the suit allowing a little too much water in at the neck. If you have a more athletic body shape, I don’t think you’d have the same problem, though, and it was fine for a dip and breaststroke. The soft detail around the arms and thighs ensured no chafing in these areas that are prone to friction.
Although it’s a wriggle to get on, it feels fantastic when you get there. With every sale, a donation is made to the Rivers Trust, a charity that helps maintain the health of rivers in the UK.
It didn’t make the final cut because … it doesn’t have a zip – getting my whole body through a tight neck hole was interesting!
Suitable for: wild swimming and short dips; material: 90% limestone neoprene, 10% ultra-flex Lycra lining; sizing: UK8-18
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£159.99 at Chilly Swim
£159.99 at Outdoor Swimmer Shop
Marks & Spencer Goodmove scuba padded long-sleeve swimsuit
Best for: high-street value
The £45 price tag got swimmers chatting on social media when this went on sale earlier this year, with many wondering if it would be any good. The answer is yes: it’s a great entry-level suit at a good price, and it’s comfortable and true to size.
The high neck and long arms kept the chill off my upper body. The zip at the front is robust, and the ideal length to get the suit on and off with ease. The thicker, almost wetsuit-like material kept my core warm and I was able to get a decent 20-minute swim in the water.
The arms were a good length. The thicker fabric was great but became heavy when wet, and the suit took a long time to dry. I wouldn’t want to wear it for a competitive race, but for social dips and heads-up breaststroke swims, it worked well. I don’t like padding in my suits, so I love that you can remove the pads.
It didn’t make the final cut because … the sleeves are too wide and have too much material, which flapped and caused drag, losing some of the warmth.
Suitable for: outdoor dips, longer swims and paddle sports; material: body 80% polyamide, 20% elastane (exclusive of trimmings); lining 100% polyester; mesh 87% polyamide, 13% elastane; padding 100% polyurethane; sizing: UK6-24
£45 at Marks & Spencer
Alpkit Dulsie long-sleeved swimsuit
Best for: longer bodies
Alpkit has been a go-to wetsuit brand for swimmers for some time; the Dulsie swimsuit is designed for swims when you don’t want to wear a wetsuit but do want a bit of extra coverage, whether that’s against the elements or for sun protection. It’s made from an ocean plastic waste recycled yarn that’s hard-wearing and durable in chlorine and saltwater.
The fabric was thinner than I was expecting, but it did keep the chill off my upper body and arms. This is a no-frills sort of suit, with a basic but effective design. The front body panel is lined, which offers additional core warmth and bust support. Sizing was generous; many swimmers prefer longer body suits, and this would be great if you’re taller or rounder in the middle. The zip is strong and long at the back, with a decent pull, which makes it simple to take on and off on your own.
It comes with a three-year bond, which means Alpkit will repair or replace it if there are any issues.
It didn’t make the final cut because … the whole suit isn’t lined, which could make a difference to the overall warmth. As soon as the sleeves got wet, it felt cold against the skin and lost the benefit a little.
Suitable for: outdoor dips and those with longer bodies; material: 78% Econyl, a recycled material made from ocean plastics and nylon waste, 22% spandex; sizing: UK6-20
£44.99 at Decathlon
£44.99 at Alpkit
Davy J bonded long-sleeve swimsuit
Best for: paddle sports
The bonded fabric – two pieces of fabric bonded together to make a 1mm-thick material – offers an alternative to neoprene if you have a skin allergy or want a more environmentally friendly choice. This thicker fabric is reversible, and feels great against the skin, with a sculpting effect. It gave me extra warmth around my core, while the long sleeves and high neck kept off the elements.
The panelling and seam structure around the armpits and shoulders provide support across the bust while still being flexible enough to allow ease of movement – which can be a problem with sleeved suits. The thumb holes are a great addition and something no other suit offers. They not only keep the sleeves in place, with less drag when swimming but are also great with gloves.
Davy J offers a repair service on all suits and an upcycle scheme for when they reach the end of their lives. The latter means you can send back the suit and get 15% off a new one, while your old suit is turned into something else, such as a buckle on another suit.
It didn’t make the final cut because … the leg cut is so high. But I know many swimmers who love a high cut for ease of movement around the thigh joint when kicking or for paddle sports.
Suitable for: outdoor dips, longer swims and paddle sports; material: 78% Econyl, a recycled material made from ocean plastics and nylon waste, and 22% elastane; sizing: XS-2XL
£160 at Davy J
What you need to know
There’s a lot of opinion in swim circles about what you should wear in cold water. For cooler temperatures, wetsuits are an obvious choice. Designed to provide thermal protection when wet, they work by letting water into the suit, creating a thin layer of water between the rubbery fabric and the skin, which then warms up and insulates the swimmer.
Purists will tell you it’s not “wild” swimming if you’re in a wetsuit, and those chasing the endorphins from a cool dip won’t want a wetsuit to get in their way. You could also argue that the time it takes you to get in and out of a wetsuit isn’t worth it when weighed up with the time you will spend in the water at this time of year. As a result, many swimmers prefer a normal swimsuit or trunks and accept that an outdoor swim will be more of a dip. The swimsuits above offer a third option.
Ultimately, swimwear should be snug, but not tight. It should feel like a second skin, but not leave red marks when you take it off. But if it’s too loose, it will fight with the water, causing drag and discomfort. A lot of wet material against your skin can make you colder, too.
When it comes to design or style, swimwear should suit the type of swimming you aim to do. If you’re having a leisurely dip, most swimwear will be fine. But for longer, more physically demanding swims, seek simplicity and function over style. Zips need to be strong and not cause chafing. Thicker straps will support bigger busts, while thinner or cross-over straps can allow for greater movement of the shoulders. Padded swimwear will soak up water, drag while swimming and feel colder, but it’s down to personal preference and whether you like padded cups for extra support or comfort. Recycled fabrics are more resistant to chlorine and saltwater, and they are more sustainable.
All swimwear is machine-washable, but to lengthen the life of your swimsuits you should rinse them in cool water after each use, especially if you’ve been swimming in chlorine or saltwater. You only need to machine-wash every two to three wears, and even then a cool wash will be good enough. Never tumble dry swimwear.
What you should know about cold water swimming
In my experience, swimmers are often more resilient, productive and positive when regularly swimming outdoors. It can improve your mood, relieve stress and maybe even have a positive effect on immune function. If you want to try cold water swimming for the first time, it can be a good idea to start when the water is warmer in late summer and continue as the water and weather cool.
All water below body temperature will feel cold, and understanding how your body responds to this is essential for swimming outside. When entering cold water, cold-water shock can be an instant reaction – this is when you gasp, take a large breath and find it hard to exhale or control breathing. To overcome this, it’s best to enter water slowly, but consistently.
Look for a swim group, open-water coach or supervised venue. There are plenty of experienced swimmers and experts in the UK to help get you started. Swimming at a supervised venue will not only provide lifeguard cover when swimming but also give you a community of swimmers to help you get started.
While there’s a lot of anecdotal evidence and some studies suggesting cold water can aid overall wellbeing, if you’re merely enduring winter swimming rather than enjoying it, ask yourself whether it’s really worth it for you.
Ella Foote is a freelance journalist, author, editor and outdoor swimming expert. She is an intrepid swim explorer, constantly seeking out new rivers, lakes, ponds, seas and pools to plunge into. She enjoys swimming in all seasons and has completed swims such as a Channel relay crossing, a 24-hour swim challenge, the Thames Marathon 14k and the Dart10k, as well as smaller more joyful dips and dunks across the world. Ella is director of Dip Advisor, a swim guiding business helping people enjoy wild water, an open-water coach and RLSS open-water lifeguard. She also teaches swimming to children and adults. You can follow her and her swimming on Instagram
