The Fundamentals Of A Wetsuit

If your next adventure involves taking to the water, adding a wetsuit to your kit list can make a huge difference to keeping you warm and comfortable in the water. But how do they work exactly and what type should you go for? Finding a wetsuit that works for you is key to its effectiveness. It can be a tricky business, but by thinking about how and when you want to use your wetsuit, you can start narrowing it down by type, season, size, and material. Our expert guide will give you all the info you need about how they work and what to consider when choosing, so you can find a wetsuit that will best suit your water-bound adventures.

The main function of a wetsuit is to keep you warm in the water. Made using a synthetic rubber called neoprene, they have very tiny holes in them that allow water in but not out. Because water is a great insulator and conductor of heat, the suit works by trapping a thin layer of water between your skin and the neoprene, which is subsequently warmed by the heat from your body. Alongside the suit itself, this warm, thin layer acts as an additional layer of insulation, helping keep your body temperature up. 

Both wetsuits and drysuits are used to provide insulation from cold air and water temperatures. The main difference is in the material and the activities you use them for.

Wetsuits are designed to keep you warm when wet, making them perfect for pretty much any activity that involves you being in the water. They provide great maneuverability in the water because their tight fit is like a second skin that reduces drag and adds buoyancy, allowing you to be more athletic and smoother in your movements. If you’re swimming in open water, surfing or wakeboarding, or generally spending a lot of time moving in the water, a wetsuit is what you’re after.

Drysuits, unlike wetsuits, are completely waterproof, but are not designed to keep you warm on their own. They fit more loosely like a shell, allowing you to have warm layers underneath that are subsequently kept completely dry. Although much bulkier and more restrictive in their movement whilst in the water, for activities where you are on, but predominantly out of the water, like kayaking or stand-up paddle boarding, drysuits are a good choice. Especially when the conditions are very cold, because you’ll be able to add additional layers of warm clothing beneath the suit which will stay warm and dry even when you get splashed or take an unexpected, but temporary, plunge.

Wetsuits come in many different shapes and sizes, designed to work better depending on the activity and conditions. So, before deciding on a wetsuit, it’s worth thinking about when, where and for what activities you intend to use it. Here are some factors you’ll want to consider:

Whatever you use your wetsuit for, the single most important thing to get right is the fit – which needs to be snug and tight all over. If there is excess material in places, or if the cuffs or neck are too loose, it’s going to let too much water in and negate all its insulating properties. Don’t be taken aback by the tightness of a wetsuit when you first put it on. Although it may feel a little snug at first, this is how it should feel when dry. Wetsuits differ slightly in size and shape for men, women and children but the key is to keep trying until you find the one that offers the correct fit for you. 

When it comes to cut and thickness, think about what activities you want to do, where you want to do them and at what time of year. That’s because water temperature is one of the primary factors to consider when selecting the most suitable cut and thickness of wetsuit for you.

Shortie wetsuits cover the torso, upper arms and thighs, allowing for less restricted movement in the water. They are more often used in the summer months because they offer great flexibility and comfort in warmer water. If your water activities take place solely in the warmer months, you’ll enjoy the comfort, freedom and flexibility of a shortie whilst still staying sufficiently warm.

Full length wetsuits cover the whole body apart from your head, hands, and feet. They are generally thicker than shorties and more suitable for colder conditions. If you’re planning to spend time in the water beyond the summer months, in areas with cooler water temperatures, or if you just prefer the feel and added protection of more body coverage, they are a smart choice.

The thickness of a wetsuit usually varies between 3-5mm and determines how warm they are in the water. The thicker the neoprene, the warmer the suit. Individual wetsuits have two thickness sizes (such as 3/2mm or 4/3mm). The first number refers to the neoprene thickness around the main torso of the body to ensure your core is kept warm, and second number refers to the thickness around areas such as the arms and knees, or anywhere which requires greater movement.

Average sea temperatures in the UK can range from as high as 15-20C in the summer and 6-10C in the winter depending on location. As a guide, 3/2mm is good for summer temperatures. 4/3mm will generally get you from spring to autumn. 5/4mm or thicker is a must for winter. But again, personal choice is the key factor and if you feel the cold, there’s nothing wrong with going for a thicker wetsuit if that’s your preference.

When it comes to zips and stitching, these create holes in the neoprene meaning that all important thin, warm layer is negated as colder water gets into the wetsuit. That’s why having the right stitching and zips are important to the performance of your suit. Here are some options to think about:

There are generally three types of zips on most wetsuits:

Back zip wetsuits have a zip leading from the base of the spine to the back of the collar. On the plus side, this creates a large opening making it easier to get in and out, but on the downside, back zip wetsuits often have reduced flexibility and a looser collar, meaning more water can flush through which you’ll definitely notice on colder days.

Chest zip wetsuits have a flap and zip across the chest. A popular choice, these suits have a smaller opening than back zip designs, therefore improving flexibility and giving a tighter seal around the body, so you keep warmer in colder water. However, getting into chest entry suits is more time-consuming and involves entering through the top of the wetsuit, pulling the flap over your head, and then fastening the chest zip to secure the fit. But what you lose in time getting it on, you definitely get back in terms of comfort and warmth.

Zip free wetsuits are the most comfortable and flexible on offer because having no zip on the wetsuit makes it lighter and more watertight. Usually a pricier option, the overhead design is similar to the chest zip but you tighten a cord instead of fastening a zip and increase the warmth of the suit and reduce the level of water flush. 

Stitching on your wetsuit involves making holes in neoprene to pass a thread through and these holes can let water in, so the type of stitching is important when considering how warm and strong a wetsuit will be. Here are the common types of stitching used in wetsuit construction:

Overlock stitching is the simplest way of joining two panels of neoprene, but the least effective at keeping water out. This stitching method usually found is summer wetsuits or cheaper wetsuits. The two edges of the panels are rolled together and then stitched to hold them together. Overlock stitching offers less flexibility of the seam and can leave a bulge on the inside of the wetsuit, which can sometimes be uncomfortable and result in chafing.

Flat lock stitching is the overlapping of two pieces of neoprene and then stitching the seam together. The hole left by this zigzag stitching method makes them more breathable and cooler to wear, making them great for summer use but less so for colder water temperatures.

Glued and blind stitched (GBS) wetsuits are of a higher quality. Neoprene segments are glued together and then stitched halfway through the material to make the seam as watertight as possible. Because the stitching doesn't go all the way through the wetsuit and leave any holes, the amount of water absorbed is kept to a minimum. The less water that enters the wetsuit and stays trapped inside, the warmer your body will remain which is crucial for winter wetsuits.

Welded seams are generally found on higher end wetsuits. They use a silicon-based watertight seal to join the neoprene panels together, making a 100% waterproof barrier. This is possible because a welded seam doesn't make any holes in the neoprene, so water cannot leak through. As a result, you keep warmer whilst also benefiting from added durability and flexibility compared to a GBS seam.

Whilst buying the right wetsuit is paramount, looking after it once you have it is important too. Doing so means it will perform better, for longer and you’ll get many years of good use out of it. Here’s a few top tips for looking after your wetsuit.

- Be gentle when putting your wetsuit on. The tight fit can make the whole operation a little bit tricky, but yanking your suit on will put undue stress on the seams and zips. Slow and smooth is the best way. Start at the bottom with your feet and slowly work your way up in stages, rolling the suit up as you go. Similarly, take as much care whilst taking it off. Work in the reverse and, as before, take your time. Try not to pull too much on the suit if it’s being stubborn, as this can result in torn neoprene, blown seams and a costly repair. 

- Once it is off, leave it inside out to dry, as this will cause less stress on seams. As soon as you can, rinse out any saltwater with cold, clean, fresh water help preserve the seams as well as the as performance and elasticity of the neoprene. 

- Once clean, leave your suit to air dry inside out, but keep it out of direct sunlight which can dry out the neoprene. When wet, rather than hang it by the shoulders, hang it by the waist using a large plastic coat hanger or a washing line to avoid damaging the shoulders. Golden rule - never wash or dry your wetsuit in a washing machine or tumble dryer as this is a sure-fire way to destroy your wetsuit.

- Once fully dry, store your wetsuit in an area away from direct sunlight that is cool and dry. A large, wide non-metal hanger that supports the shoulders properly is ideal. Never store a suit that’s wet as this may result in mould forming or it becoming stretched when hung.