Dry Suit or Wet Suit

Wet suitDifferent people will feel the cold differently. However, there are some basic guidelines. If the water temperature is below 10°C (manufacturer guideline, personally we think anything below 15°C) would warrant a dry suit. This means, if you intend to dive in the UK or any colder climates, it is advisable to dive in a dry-suit. Apart from keeping you warm underwater, it also helps to ward of the chill outside of the water, as the wind doesn't cool you off.

A wet-suit contains seals around your neck, wrists and feet - with a secondary seal to go over the boots (and sometimes the gloves as well). The aim is to get a single water-flush into the suit, which is warmed up by your body and stays inside the suit, giving you "protective layer" which seals you against the "outside" water.  

Temperature guideline for suit types

It is the type of diving you wish to do that determines the type of suit you should wear. The thermometer drawing gives you guideline. However, different people will feel the cold differently.

 

If you intend to dive in the UK, especially all year around, a dry suit is a good investment. You can use the suit all year long and adjust the type and quantity of under suits you wear. 

However, even in warmer waters (e.g. Egypt in winter 26°C) after an hour you will get cold in a shorty - diving in a full length wet-suit is recommended.

What you need to consider is not only the diving itself, but the total dive trip, consider the following questions:

  • Do you need to stay in your kit all day, and also between dives? 
  • Most divers are comfortable for about an hour in their kit before they get cold? How will you feel if you have to stay in the water for 2 or 3 hours (as you are waiting for the dive boat)? You should have enough insulation to "survive" a longer time in the water
Guideline for type of diving suit
Wet suits

Introduction

The wet suit works by trapping a layer of water between you and the suit. Your body warms the layer up and insulates you against the outside water. So when you jump into the water, you are going to feel a rush of cold water running into the suit - a bit of a shock sometimes, but it soon warms up. As your body uses its own heat to warm the water up, it is vital the suit is not too baggy, as you would have to warm a larger water volume up and the water would also cool down as it is moves away from your body. The water layer in a wet-suit is a thin layer and you shouldn't feel the water "rushing" around Therefore, the suit needs to fit tightly on your body - so don't buy a surface sport wetsuit (e.g. for wind-surfing), they are too baggy, are designed to be flexible for arm movements and have poor heat retention properties. Ensure you buy a scuba diving wet-suit, it will have seals around the neck, wrists and feet and will be a very snug fit. Don't be tempted to buy one at the supermarket, they are made from extremely low quality neoprene (usually synthetic neoprene), which doesn't have the warming qualities, is extremely more buoyant and is likely to rip easily.

Go to a shop and try a variety of them on. They should be quite difficult to get into, pulling the suit on, you may need somebody to even help you get them on initially (they do stretch over time). Once you've got the suit on, it should feel tight (without restricting your breathing), you should be able to move around in it - check your arm movement and try to squat.

Shorty

In warm water, the shorty will cover your torso, shoulder and thighs. It will enough to keep your body warm and will keep you warm even on a deeper dive in warmer waters, where you might encounter a bit cooler water (thermocline) at depth.

 

Full body

It is in effect a shorty with full arm and leg length. There are a couple of key differences. Check the suit has a proper neck seal (usually a neoprene fold), wrist seals and layered foot seal (i.e. the inner seal goes into your boot and ankle seal - usually with a zipper goes over your boot). There will be different thickness available, most of the manufacturers have a thicker neoprene section around the mid-section, giving additional warmth for your kidneys and lower back.

Oceanic ProSteel Wetsuit

  

Layer system

In the past you would have bought a two layered system (considering of an armless dungaree type trousers) and a jacket (with a crotch strap). These types have effectively been superseded with a more practical solution. The newer system consist of a shorty and a full-body, allowing you to use the suit in a variety of conditions - shorty, full body and layered - effectively giving you three suits in one. The varieties are quite endless, best is to get advise from a number of different shops. Our favourite was the Oceanic Shadow - but it has been discontinued.

 

Options

Plush Lining - the inner lining of the suit is made of tiny woven loops, giving a bit more space between the suit and the body - it gives a bit more warmth. Every few years it comes back into fashion.

Merino Wool - absorbs water and swells up. Merino wool can hold up to 30% more water , is very fine and soft against the skin (it doesn't scratch). In addition, it is exothermic (i.e. releases heat when it gets wet), which means it helps to warm you up and it doesn't compress as much as synthetic material (which cannot absorb water). Consequently, tests by the British Technology Group have shown that Merino Wool wetsuits offer an improved thermal efficiency of about 20% to 35%.

Titanium Lining is a reflective layer build into the neoprene suit. It reflects your body heat back into the suit, reducing heat loss and "reheating" the water.

Zips - there are metal and plastic zips. Metal zips last longer, but are prone to corrosion, while plastic zips are less robust but more comfortable and easier to maintain. Good suits will also have ankle zips, making them easier to get in an out.

Zip flap - a wet-suit should have a zip-flap, this is a piece of neoprene on the inside of the zip, that sits against your skin. This flap ensures your skin doesn't get trapped in your zip and is more comfortable to wear. In addition, you have a protective layer between you and the zip and therefore a better seal, which stops water from flooding through the zip.

 

Wet suit maintenance

Wet suits are very easily to maintain. After usage they should be washed out with fresh water and then allowed to dry naturally out of direct sunlight. If the suit starts to smell (there are two types of divers - divers who pee in their wetsuit and divers who lie), wash it out with a neoprene shampoo. If you don't have it on hand (in an emergency), we have used a mild washing up detergent - it works, but it takes ages to wash out the detergent (as it foams too much).
Dry suits
ND Divemaster

Dry suit types

A dry suit does exactly what it says - it keeps you dry while diving. It traps a layer of air (gas) between you and the water. Air is a better insulator than water, to avoid too much pressure, you have to equalise the air space inside your suit and to do this you have an inflator valve (usually on your chest) and a cuff / auto dump to release the excess gas from your suit. It does require additional training, but most divers in the UK will dive in dry-suit all year long.

There are effectively two types of dry-suits:

Trilaminate - a thin layered dry-suit with no thermal qualities. It is easy to repair, to get on and off, but it does require a thick thermal undersuit. 

Neoprene

- a thick neoprene suit, which is very hard wearing, very warm, but more difficult to get on and off. In addition, they are very buoyant and you will require additional weight to compensate. Our favourites are the Northern Diver Divemaster (see photo) and the Beaver Iceberg Ultra Drysuit.

 

Sizing your dry suit

A dry suit must not be too big (or too small). If it is too big, the gas inside the suit can move around too much giving you significant balance and buoyancy problems underwater. The best thing to do is to wear a pair of jogging bottoms and a sweater when trying on a dry-suit. Ensure the suit fits comfortable and your able to squat and give yourself a hug at the same time, if it pulls, then it is too small. There should be no excess material around your legs and arms. The boots should allow you to wear thick socks - guideline - go for one size larger than you normally wear. If the boots are too small, you will get cramps in your foot.

If you can't find a suit that fits, most manufacturers will custom make your suit - depending on the manufacturer the cost is an additional 10%. Ensure you go to a dive shop to get measured up.

Dry suit valves

Dry suit valves

Valves enable you to add or remove gas from you suit. A dry suit will have an inflator valve usually fitted somewhere on your chest. An additional low pressure hose from your regulator first stage will be attached to the valve. Depending on the design you and your preference, you may have an auto-dump valve fitted on your left upper arm or a cuff dump on near the left wrist. The auto-dump valve will automatically release excess gas once it is set correctly (something that is taught on the course). With a cuff dump, you just raise your arm and the excess gas bleeds from the valve (a very simple and reliable method). Picture shows from left to right an auto-dump, cuff dump and inflator valve from Apex.

 

Zips

Dry suit zips are waterproof and extremely expensive to replace. You must ensure nothing gets trapped (it can bend the zip and then it will leak) and it should be maintained based on manufacturers guidelines, usually using zip-lube, beeswax or specialist material supplied by the manufacturer.

 

Seals (latex and neoprene)

To ensure no water enters the suit, the neck and wrist seals must be tight. There are two types Latex (thin) and Neoprene (thick). Latex gives a better seal, but are prone to ripping and require regular replacement. However, the are easy to replace and a your local dive shop is likely to replace them for you. Important when putting on your dry suit is to use a bit of a water based lubricant or un-perfumed talcum powder to allow you to "slip" your wrists and neck through the seal.

 

Options

Pockets - most suits can be customised with pockets - very useful to put spare torch, mask, dive knife and other assorted equipment. 

Comfort zip - useful for blokes to get an additional zip fitted, it allows for easy access to go for a pee, but it does mean maintaining another zip 

Pee-valve - more and more common - a mechanism allowing you to pee underwater - a tube via a valve allows you to pee while underwater (and on the surface). Once you have one, you don't understand why you didn't get one fitted years ago. 

Electric undersuits - a number of options have emerged in recent years - Typhoon heated belt (okay, but not brilliant) and the Santi electric heated diving undersuit (fantastic, but very expensive). An alternative is too use electric heated vests such as used in motor-cycling, but this is very dangerous - should your suit fail and flood, these batteries will short circuit and become very hot (they can even cause fire underwater in your suit). So this is something, we definitely wouldn't recommend.