Water conducts heat away from the body 25 times faster than air, so adequate protection in water below 32° (the temperature at which the body can retain its own heat) is essential for comfort and safety.
The first choice when deciding on which exposure protection best fits your needs is to determine what water temperatures you plan to dive in.
If they will be below 10°C a drysuit will almost certainly be best. Above that temperature a wetsuit would normally provide the best solution.
Drysuits offer one significant advantage over wetsuits – they keep you warm out of the water as well as in it because they withstand the cooling effects of the wind.
The major disadvantage of the drysuit however is its cost and the additional training required to use it.
Wetsuits work by trapping a layer of water next to your skin, which your body heats and that water in return keeps you warm. The down side of this is that cold water must first flood into the wetsuit which may be somewhat uncomfortable!
It then takes a few minutes to heat up and gradually the benefits can be felt. However once the suit is up to temperature it will be very comfortable. Wetsuits are generally made of neoprene and a good quality neoprene suit should last you a reasonable length of time.
There are many cheap suits available to buy which are made of synthetic neoprene which has a much shorter working life (and is prone to ripping), lower thermal properties, and increased buoyancy.
The best way to ensure you buy a wetsuit manufactured using a good quality neoprene is to always purchase wet suits from large scuba manufacturers like Fourth Element, Mares, Waterproof or Seac Sub, not at your local supermarket! Scuba diving and snorkelling wetsuits are also cut differently from surface sports wetsuits like those used for wind surfing.
Surface sports wetsuits tend to be thinner and baggier around the shoulders to allow for more arm movement which allows maximum flexibility but inferior heat retention which is so important when spending a significant amount of time submerged.
The style of suit you will need will be dictated by the water temperature you will be diving in.
Shorty wetsuit – In the warmest water a shorty wetsuit will be ideal, with short arms and legs where only the body is covered. This is perfect in warm water where you will be diving deeper or longer, possibly below the thermocline where you need something just to keep the chill off.
Full length steamer – This is essentially the same as a shorty wet suit but these suits include full length arms and legs. These suits offer additional warmth as well as extra abrasion protection and are ideal when diving near wrecks to avoid minor cuts.
Layer systems – In recent years layered systems have replaced traditional semi dry suits to offer maximum warmth and versatility. Two or more layers allow additional and better water trapping than the old single layer technology. Layers also allow you to use thinner neoprenes to create extra warmth.
Semi-Dry Suits – Semi dry suits are a wetsuit with seals and features similar to a drysuit but they are made to allow some water in. These suits have ankle, wrist and neck areas made of a special material to reduce the flushing effect of warm water being washed out of the suit by cold water entering.
As a general rule there are 3 main thicknesses of wet suit: 3mm, 5mm and 7mm. After this you’re moving into dry suits. The thinner the suit, the better flexibility of movement you will have but the less warmth and buoyancy. High quality neoprenes such as DuPont neoprene offers good warmth to buoyancy ratios, imitation neoprenes often have low thermal properties and undesirably high buoyancy properties – these should be avoided.
We’ve come up with this chart to help you choose a suit for the location you’re planning on diving in:
Bagginess in a wetsuit allows for pooling of large amounts of water which the body cannot heat sufficiently, resulting in a cooling effect which is the exact opposite to what is desired. Ill fitting suits may also suffer from flushing where the warm water is flushed from the suit by cooler water entering the suit.
A wetsuit should therefore be snug, not so tight that it could restrict breathing or blood flow, but comfortably tight. Wetsuits can be quite a struggle to get in and out of so when trying one on, if you need a hand initially and have to jump about to get the suit on properly, don’t be too hasty to assume that the suit is too small. It probably isn’t, you want it pretty tight.
If it feels comfortable and you have an adequate amount of movement in it, it should be fine. If you can kneel down on one knee and touch the back of your neck at the same time without too much restriction then the suit fits you fine.
Scuba suits have a longer zip than surface suits which make them somewhat easier to get on and take off (the reason that surface suits have a short zip is because a zip will not stretch to allow for the extra movement required in say windsurfing. The neoprene panel at the base of the zip is made as long as possible to allow the back of the suit to stretch – a feature not necessary for scuba diving.)
Some people may not fit into standard size suits and for these people the only resort is to have a suit made to measure, which can be expensive and does not insure that the suit will fit perfectly.
Due to the problems associated with made to measure suits and the risk that the suit will not meet the customers expectations, it is sadly not a service that we can offer. If you decide to have a suit made to measure however and you can find a reputable manufacturer, you should ensure that you are measured by a trained, experienced person because if you get even one of the many measurements wrong, you will have a very strange shaped and badly fitting suit!
Plush Lining – Plush lining is another concept in wetsuit linings that reduces water movement inside the suit and increases the speed that a wetsuit will dry between dives. This type of lining is best described as tiny loops of weave, maybe only 1-2mm in length that stand proud of the internal surface. Again the concept is to trap more water within the suit, the more warm water in the suit the warmer the diver! (Although remember, a baggy suit is taking this concept too far). This lining also gives the inside of the suit a very soft and comfortable feel.
Zips – There is always strong argument to whether metal or plastic zips are best. Metal zips are obviously the strongest but are prone to corrosion if you don't fry them properly, while plastic zips are less robust but are impervious to corrosion. Our best advice is always go for a well known zip such as YKK. Ankle zips on thicker suits do make getting into the suit much easier and should be considered.
Kidney and Spine Pads – Some suits offer additional material over the kidneys and down the spine as these are key heat loss areas and when wearing a tank, they can significantly increase your comfort. This feature is normally only seen on thicker suits.
Zip Baffle – This is a layer of material that sits behind the zip to stop water flowing through the zip but also to increase the comfort of the suit by not having the zip against your skin and slowing water transfer.
Titanium Lining – A recently new addition to the neoprene of modern wetsuits in a titanium covering. To see this simply stretch your suit inside out and you will see an almost metallic reflection on the material. This helps stop heat lose by bouncing it back towards your body. Not only does this help reduce heat loss, it also reheats the water within the suit as the heat is reflected creating a double positive effect.
As a wetsuit ages, the bubbles in the neoprene become smaller (crushed to be accurate) and this in turn means the warmth offered by the suit is reduced. The bubbles act like double glazing in your windows so with less insulating gas bubbles it doesn't work as effectively.
There is no way of repairing this damage and a new suit should be considered. If however you have purchased a suit that is not thick enough or your existing suit has become crushed you can increase the warmth potential by layering.
Simply wear a “Rash Vest” which is a thin Lycra like tight fitting T-shirt, this will allow water to be trapped more efficiently which in turn improves your warmth. If you think you need more warmth, a 1.5mm or 0.5mm suit or vest can be worn under your main suit.
As with any dive kit your wetsuit or drysuit should be washed in fresh water after use and then allowed to dry naturally out of direct sunlight. After a while you may find the suit will begin to smell (especially if you pee in it). To counter this you should wash the suit in proper neoprene suit shampoo.
The correct shampoo helps preserve the neoprene and remove the smell. The worst thing for real neoprene wetsuits is ozone which attacks the neoprene and can degrade it leaving you with nasty sticky patches on the suit, usually at stress points, which do at some stage (usually as you put the suit on for your dive!) tear.
If you plan on not wearing your suit for several months you should (once it is absolutely dry) gently fold it (no sharp creases) and place it inside a black bin liner and store in a cool dark place to stop the ozone attacking the material.
If you plan to use the suit again in the near future, hang it on a wide shouldered hanger (use of wire hangers is to be avoided as the weight of the suits on the thin wire means the suit creases badly on the shoulder and can even cut into the suit.) Specialist hangers are available from us and can be used to store other scuba diving gear to.
Some creases in neoprene can be helped by simply wearing them. As you wear the suit and move around it stretches the material and can loosen up the crease but some creases are too far gone.
Dry suits work by keeping the water out whilst trapping a layer of air next to your skin which is a better insulator of heat than water. There are two major types of dry suit – trilaminate and neoprene.
Both have distinct advantages but in the end it comes down to personal choice.
Auto Dump (Left) Inflator (Middle) Cuff Dump (Right), not to scale.
The valves allow air to enter and exit the suit whilst submerged similar to your BCD.
The inflator valve which is connected to your 1st stage, allows air to enter the suit, by simply pressing the button on the front of the valve. This valve is generally located in the centre of the chest. Air from your first stage comes via a hose generally routed under your left arm (but not always) and connects to the inflator in the same way your low pressure hose connects to your BCD inflator mechanism.
There are two types of dump valve available on dry suits – cuff dump and auto shoulder dump.
The cuff dump as the name suggests is located near the wrist on the cuff and is operated by simply raising the arm to the highest point where the air pressure within the suit causes the one way valve to open and expel the excess air.
The shoulder or auto dump is again as the name suggests located near the shoulder but is more sophisticated than a cuff dump. An auto dump has a pressure sensitive spring which allows it to automatically bleed excess air from within the suit. You can adjust the tension in this spring to completely shut the valve or open the valve very easily depending on your needs.
The Shoulder dump is the most popular as cuff dumps can allow water into the suit when on the surface because they require the pressure of the water to keep the valve closed.
When deciding on the correct size of dry suit you will need to consult the manufacturers size chart. We have found that it is best to take your measurements over a sweat shirt and jeans. The suits are generally cut slightly larger than the size charts, but this extra layer allows for movement and an undersuit.
When you try the suit on you should wear exactly what you plan to dive with underneath it (such as an undersuit) and the suit should then be closed, zipped up and the air expelled by pulling out the neck seal to release the air and then crouching down. When the majority of air has been released you should let go of the neck seal to prevent air refilling the suit when you stand up.
Then you should try to kneel, with your feet flat on the floor in the style of a cossack dancer (really, it’s not a wind up). This is to make sure the legs are long enough and if you find it pulling and uncomfortable in the crotch area, the suit is too short for you. When you first hold the suit up, you will look at the length and proclaim it is way too long for you.
However as the material does not generally stretch it is critical that the suit is long enough to allow your legs to fully bend otherwise climbing boat ladders becomes difficult if not impossible. Whilst in your cossack position wrap your arms around yourself as if trying to keep warm, this makes sure you have enough width across the shoulders to move freely.
The boots should not be too large and again if you plan to wear thermal socks these should be warn when testing the boots. If the boots are too large, air can migrate and cause buoyancy problems; if too small your feet will become sore. So as a general rule of thumb go for your standard shoe size or one size bigger if using thick thermal boots.
On a drysuit there will be tight seals at the neck and wrists. Some manufacturers tend to use neoprene seals and some use Latex. Latex seals tend to be the most efficient seals, but over time they will perish. Luckily they can be replaced and home kits are available for you to do this yourself, although from experience, once you have tried to do it yourself to save money, the next time you need to get it done you will no doubt pay the extra for someone else to do it for you! We always recommend that a professional technician replaces the seals since a flooded suit due to a failed seal can be a frightening and dangerous experience.
When you receive your suit, the seals will almost certainly be too tight and if you look on the inside of the seals, you will notice thin rubber rings. These show where the seal can be cut back to, to improve the comfort and fit of your seal. A word of caution, no matter how tight the seal feels when worn, only cut off one ring at a time to make sure you don’t cut too much and end up needing a new seal straight away and always use a sharp instrument. The seal should still be tight after trimming as over time the seal will loosen, but it should not be too tight to cause dizziness or tingling.
The waterproof zip fitted in your drysuit is the single most expensive element of your suit. Care must be taken to ensure its continued good operation. Whenever closing the suit make sure your undergarments never get caught in the zip as this may cause it to leak (even after you have removed it). Try to regularly lubricate the zip; specialist products such as beeswax and zip lube are available but you should consult your owners manual for their recommendations.
It is possible for men's drysuits to be fitted with a convenience zip (saves removing the whole suit should you need take a pee) and although in theory this a good idea, few divers in practice find them much of a convenience and it is another zip to take care of.
Pockets can be fitted to your suit both during construction and after construction. Pockets are useful for carrying slates and small tools and are normally situated on the thigh. If used at all, they quickly sag and look heavily used and in a relatively short space of time, can make the suit look old and worn.
That said if you need pockets to carry extra things they are a good solution. Another option is to buy a strap on thigh pocket which can be removed and replaced as necessary.