Excited at the prospect of owning their own gear, many divers buy new equipment without really thinking about whether it’s right for them. This is especially true of drysuits. It’s common to hear people say, “I wouldn’t have bought this one if I’d known a bit more about them.”
Given that it likely will be your most expensive piece of dive gear, it makes sense to learn more about them before buying your first drysuit. Here’s what you need to know about the most popular types of drysuit — neoprene and membrane — along with some details on extra features to help you make the right choice.
There are three main types of neoprene drysuit: crushed, compressed, and foam. Each has specific characteristics depending on how much it’s been crushed and the shape of the air bubbles trapped inside the material, although differences are nominal to the average diver. In all three cases, a rubber lining sandwiched between the neoprene creates a barrier between you and the water. Neoprene suits are thicker than other types of drysuit, so they offer better thermal protection in frigid water. In 36 F (2 C) water, for example, you’ll feel noticeably warmer compared with other types of drysuit. They also stretch a little and provide some buoyancy if the suit floods, with the neoprene acting somewhat like a wetsuit. However, the bubbles inside the suit’s material mean the buoyancy characteristics will change with depth.
Given their increased warmth in colder water, why doesn’t everyone wear neoprene drysuits? Their buoyancy characteristics mean that you will have to carry more weight than with other types of drysuit, and all that thick material reduces your range of movement compared with other types of suit. Getting your arms over your head can be particularly problematic as the seams under the armpit often limit range of motion. If you are thinking of diving in a twinset, for example, you may struggle to reach the valves.
Membrane suits are most popular among technical divers because they are thin and light, and therefore offer a greater range of movement compared with neoprene suits. Different types, such as tri-laminate or quad-laminate, all offer the same characteristics. They have a hard-wearing outer layer (in some cases made of Kevlar), a waterproof butyl middle layer, and a more comfortable inner layer, which may offer very limited thermal protection. The types of materials that make up these layers will determine the weight, feel, comfort, and range of movement of the suit. Membrane suits generally do not stretch. They also do not offer much, if any, thermal protection compared with neoprene suits. The undersuit does that alone.
Unlike neoprene, water pressure does not affect a membrane suit. Only the compression and expansion of the gas inside the suit affect its buoyancy. These thin suits are appropriate for temperate and cooler tropical waters, such as in parts of Indonesia or the Galapagos Islands. They’re also light and travel easily. Using a membrane suit in colder waters means your warmth will depend mainly on your undersuit. You’ll need to think about abrasion resistance if you dive frequently in caves or wrecks, which means adding Kevlar protection that will weigh more.
To have a balanced rig, your weight distribution must be even after taking your body’s buoyancy characteristics and your equipment into consideration. Wearing a drysuit means you’ve got a second source of buoyancy to think about, and that will also affect your overall balance. Some people’s legs are quite floaty in a drysuit and others will be the opposite. To help alleviate floaty legs, you can buy gaiters that wrap around your shins. These will help reduce and slow air migration to the feet. Whether they are useful or effective is very subjective, but you should think of them more as a fine-tuning tool to slow down any air migration, rather than a cure for an unbalanced rig.
Divers also use ankle weights to address floaty feet, but these are slowly going out of fashion. Some divers swear by them while others think they’re a cheat to solving the wider problem of an unbalanced rig.
Front or rear-zip drysuit
Drysuit zippers traditionally sit across the back of the shoulders. On neoprene suits this is usually the only place to put the zip. Sturdy brass zips are the most common, but you must care for them vigilantly and they can be brittle. The back of the shoulders offer a straighter run for a brass zip if the suit fits properly. This area of the body also experiences less movement both in and out of the water, which means less stress on the zip. Keep in mind that the zipper is the most expensive part of the drysuit to replace.
A disadvantage for a rear-zip suit is that you either need someone else to zip you in or you must be particularly inventive (and careful) about hooking yourself to something to gently close or open the zip alone.
The advent of sturdier YKK plastic zips, also cheaper to replace, means that front-zip drysuits are becoming more popular. These zips are also more flexible than stiff brass. There is also a lot to be said for getting yourself into or out of your suit without help. One consideration when choosing a zipper style is how often you need the bathroom — if you’re a man — and your suit doesn’t have a p-valve. (More on these in a later article)
Custom-made or off-the-shelf
You can get a drysuit custom-made or purchase one off the shelf. It’s best to get measured — some manufacturers’ websites feature videos on how to do this properly — and send this information to the manufacturer. They’ll then recommend the right suit for you. This may mean that your suit is completely tailored to you, which may cost a little extra and take a few weeks or even months. Or, it may mean that they use a standard-size suit with larger or smaller boots, for example. This will cost less and take less time to prepare. Proper sizing is critical for comfort, effective mobility, and efficient buoyancy and balance. Never compromise on fit because of cost, if you have the means.
Are you happy to be snug in a suit with limited movement, or do you need to reach valves on a twinset? A telescopic suit gives you extra material if you need it, which folds to turn you into a human accordion around the waist. A crotch strap keeps the material in place when it’s not stretching upwards. Also, if you buy off-the-rack, a telescopic suit provides a range of sizing so there’s a better chance that it will fit you. The last thing you want is a suit that you can hardly get in to, but one that’s way too big is just as bad. It will allow air to migrate easily, which can make buoyancy control more difficult. A telescopic suit is a clever way around this.
Boots or socks
Do you want to wear your own, easily replaceable footwear (so-called rock boots), or would you rather your drysuit was all-in-one, including the boots? There are really two considerations here: how much walking you think you’ll do, and how good a fit the all-in-one boots provide. The water exit at Silfra Fissure in Iceland, for example, is around one-quarter mile (400 m) from where you gear up, over basalt gravel. Conditions like these will quickly wear out any drysuit boot if you dive in them regularly. If you’ll be diving mostly from dive boats, or will do very little walking, it’s much less an issue. Having said that, it’s relatively easy for a professional or the manufacturer to replace worn-out drysuit boots.
The main problem with all-in-one boots is that everyone has different-shaped and different-sized feet, and the drysuit manufacturers try to accommodate everyone. One brand may have quite wide boots and another brand will be narrower. Try these on before purchasing if you can. Boots that are too small can be painful, and boots too big mean your feet will come out of your fins. You can wear extra pairs of socks to compensate but that’s a band-aid, not a solution.
To me this is a no-brainer. A surface interval usually requires a bathroom break, and braces will keep the suit around your waist and its arms from dragging on the floor. Braces are usually included at no extra cost so it’s better to have them than not. They are usually attached with Velcro so it’s easy to remove them.
Wet gloves are cheap and you obviously won’t have an issue with leakage. However, in water below 61 F/16 C, your hands or fingers will get quite cold. You can choose from many different brands and can order a drysuit that comes with a particular brand.
We’ll cover undersuit selection more in-depth in another article but, in short, there are many different types. Choose from one-piece or two-piece; a lightweight, flexible skin-tight suit made of fancy materials or more traditional quilt-style suits. Regardless of what the manufacturer promises, all undersuits must trap gas that your body will then warm up.
If your drysuit is tight, there isn’t much room for trapped air. If any part of the undersuit presses directly against your body, heat will be conducted away quickly. Likewise, a thicker undersuit doesn’t always mean you will be warmer. Undersuit thickness also plays a role in the air migration around the inside of the drysuit. If you have a thick undersuit or are wearing more than one layer, it slows down the air movement. When you dump air from the suit it can take longer to vent as you ascend.
Additionally, you may think that you have the right-sized drysuit, but when you put on your undersuit, you suddenly find that your mobility has plummeted. Always factor in the thickness of the undersuit you want to wear when thinking about what size drysuit to get.
Again, look for an upcoming article dedicated to p-valves. Just as with undersuits, there are many different brands on the market. How long you intend to be in the water during a dive and how long you’ll be in the suit before and after the dive are both vital considerations. A long boat ride potentially means needing to go to the bathroom before even getting in the water. Not being able to go to the bathroom when wearing a drysuit often means that divers often purposefully don’t hydrate enough before and after a dive, which is a risk factor for decompression illness. Ordering a p-valve with a new suit means it will be professionally fitted and less likely to leak than if you retrofit one yourself. It’s nice to have the option to go to the bathroom, even if you don’t think you will use it much.
Although there is a lot to consider when buying your first drysuit, it is worth putting in some research. Talk to other divers and try on a few suits if possible. If you can take one on a dive, even better. Take your time and choose wisely, as your drysuit will be an investment you’ll use for years.