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Choosing a Diving Drysuit

Divers looking to keep warm in colder water or during long dives have more choice than ever before but the choice is a very personal thing. Some divers will swear by a neoprene suit from one manufacturer whereas another will only dive in a membrane from another brand.

Besides the obvious option of membrane or neoprene you’ll also need to consider whether you want an off the peg size, customised fit or fully made to measure, what type of wrist and neck seals you want, the type of boots you’ll need and several other possibilities.

These days most drysuit manufacturers offer some degree of customisation, especially those that either make or finish the suits in their own facilities rather than receiving a finished product from a mass production factory.

Here we will cover some of the basics of how to choose the right drysuit for you and we will start by looking at the differences between membrane and neoprene drysuits. You can find out more about the two different suits by clicking the links for more information about how they work.

Membrane Vs Neoprene

The two suits are significantly different. By themselves they offer different thermal and buoyancy properties, the fit is different because of the stretch of the materials and components such as the seals, zips type and zip placement options can be different.

Membrane Drysuits

Let’s start with the membrane variety. When we say membrane we are referring to a drysuit that is made from a fabric material rather than neoprene and might also be called a trilaminate drysuit.

The ‘Tri’ refers to the typical three layers of materials that make up the fabric which include a hard-wearing outer, a waterproof middle and a softer more comfortable inner. There are and have been drysuit that are only made from two different materials and there are some that are made from more than three.

Membrane drysuits are very versatile and the possibilities that can be achieved by a manufacturer are almost endless because there is so much choice of material combinations. If you want a heavy duty suit you might add a Cordura or similar material to the outer layer for outstanding abrasion protection, if you need a lightweight suit you go for lightweight materials that fold and roll easily.

The major weakness of a membrane suit is that it has next to no thermal insulation itself so it is essential that additional thermal layers in the form of an undersuit is also bought. This might sound like a big disadvantage but it can also be a massive advantage if you dive year round or in various dive destinations where the water temperature various.

A few pros and cons are listed below but the merits and pitfalls of this type of suit are discussed further in our Membrane Drysuit Guide.

Pros

Cons

  • Versatile – Much more design, material and component options
  • No buoyancy fluctuations due to material compression.
  • Quick drying
  • The design is more forgiving for diver weight and size changes.
  • Negligible thermal insulation – an undersuit is essential
  • The fabric has little stretch so are baggier to accommodate movement

  • Neoprene Drysuits

    Neoprene drysuits also offer some degree of material choice but generally we are choosing the thickness of the neoprene and whether it is standard neoprene or been subjected to compression or crushing processes.

    Neoprene is thermally insulating so the need for additional thermal layers is reduced but neoprene is also buoyant because it is full of tiny air bubbles which is what helps to provide that insulation. The trouble with air when diving is that it compresses as you go deeper. As with a wetsuit the neoprene is naturally compressed, the suit gets thinner and its buoyancy is reduced making the diver heavier at depth.

    To help reduce this problem manufacturers offer suits made from compressed and crushed neoprene that has been through a process of altering the structural make-up of the neoprene to pre-compress the air bubbles and therefore reducing the fluctuation of buoyancy as you dive. Compressed and crushed suits offer slightly less thermal insulation than standard neoprene because the air gaps have been shrunk and can cost a little more due to the extra steps needed during manufacturing.

    A few pros and cons are listed below but you can find out more about neoprene suits in our Neoprene Drysuit Guide.

    Pros

    Cons

  • Neoprene is thermally insulating reducing the need for additional thermal layers
  • Neoprene stretches with movement allowing for a snugger fit
  • Neoprene is buoyant and affected by compression
  • The suits tend to be heavier and bulkier to transport
  • The snugger fit is not so accommodating for diver weight and size changes.

  • Fit

    Getting the right fit is important and it is better to be able to try on different sizes with the appropriate thermal clothing for the style of suit and the expected water temperature to ensure a comfortable fit.

    There are essentially three options when it comes to sizing and fit:

    Off the peg suits will typically offer a good list of features at a very reasonable price as they can be manufactured in bulk and stored ready for distribution and purchase. The disadvantage is that they must accommodate a range of size variations so might not fit perfectly compared to a customised or made to measure suit. If you want to change the valves, add extras or modify it from the original specification this may not be the option for you as any modifications may affect the warranty.

    Customised suits provide the option of altering a standard off the peg size suit slightly to offer a better fit or perhaps change some of the components before it is finished such as swapping for a different seal system. The options available will depend entirely on what the manufacturer offers, will require extra time to finish the suit and may cost more than the standard price for the different components. As the suit has been customised for you there is the possibility that returning the suit may be difficult so it is important that you are sure about your choice and alterations.

    Made to Measure suits offer the pinnacle of fit with the suit being made to your exact measurements. Made to measure suits are more expensive and will take time to complete so it is worth the effort of being expertly measured. You will typically be able to have much more say about the components and extras fitted to the suit such as thing pocket, etc as they can be accommodated during the manufacture.

    Components

    Zip

    All drysuits are fitted with a dry zip either across the back of the shoulders or diagonally across the front of the body but there are several different styles of zip.

    The standard style of zip is made from a combination of brass teeth and rubber seal that zip together to create a waterproof seal. Brass zips are the cheapest option but are stiff, must be cleaned and lubricated to ensure correct zipper movement and can be prone to damage if bent the wrong way.

    Another option is a composite zip which are entirely made from lightweight synthetic materials. These zips are highly flexible, are much thinner and easily to maintain but may cost a little more.

    Where the zip is positioned can affect the flexibility of the suit and determine how self-sufficient you are when getting in and out of the suit. Suits that feature a brass zip are restricted by the rigidity of the zip so the suit will not be as flexible wherever it is placed. Rear zips traditionally offered better flexibility in the rest of the suit but require someone else to close and open the zip for you. Front diagonal zips allow you to close and open the zip yourself but traditional brass zips limit the movement of the suit. New composite zips significantly reduce the flexibility problems so front entry drysuits have become much more popular.

    Seals

    Seals fitted at the neck and wrists keep the suit watertight when in use with neoprene and membrane suits being fitted with different material seals as standard. Neoprene suits are typically fitted with neoprene seals and membrane suits get latex seals as standard.

    Neoprene seals tend to be more comfortable but divers often comment about a little water entry whilst diving. Latex seals are stretchy but can feel very tight when new and can deteriorate over time, especially if not properly maintained.

    Silicone seals are offer the best of both worlds, the comfort and softness of neoprene but the flexibility and stretch of latex. Silicone seals cannot be directly fitted to the suit so require a mounting ring that it glued to the suit. Silicone seals need a little more care when getting the suit on and off but do not deteriorate like latex does over time. The ring system also allows for replacement of a damaged seal in minutes rather than hours of preparation and gluing.

    Valves

    Valve design hasn’t changed in many years and there are only a few truly trusted manufacturing brands. Your choices will be whether you would like a swivelling or fixed orientation inflator valve and either a cuff dump, standard auto dump or low profile auto dump.

    The inflator valve is what allows air to be injected into the suit to increase buoyancy and maintain that thermal barrier. A fixed orientation valve is simply fitted and pointed in the general direction of the inflator hose whereas a swivelling valve can be rotated to the best position by the diver.

    Deflation valves allow the diver to vent air to reduce buoyancy. This can either be achieved via a manual cuff dump that is activated by raising the wrist sufficiently and lowering to stop. The alternative is to use an automatic valve that works on internal air pressure to open and close the valve depending on the sensitivity set by rotating the valve. These are fitted to the shoulder as this is typically the highest point when ascending and are available in standard and low profile versions.

    Boots

    Drysuits either come with a heavy duty rubber boot or neoprene socks, both of which are glued to the suit. The choice is personal but the advantage of a neoprene sock is that it allows you to pick the style of boot you put over the top of the sock.

    The integrated boot is heavy duty with a thick sole, will have good tread for traction and usually incorporate a strap retainer on the heel. They do the job and mean it is something else you don’t have to remember to bring.

    If you go for the neoprene sock option there is a wide choice of boots including the standard neoprene boots used for wetsuits which will offer an extra thermal layer over your feet or canvas style boots that are hard-wearing and offer excellent abrasion and puncture protection.

    There is a lot to think about when choosing a drysuit and will typically have a big monetary value attached to it so it is important to weigh up all the options. We are available to answer any questions about the suits we offer or sizing queries. We have a wide range of suits available in store to try on so please give us a call to arrange a fitting session with one of our specialists.