A wetsuit is pretty much an essential piece of kit for a dive, affording some protection from cuts and scrapes, but with the primary aim of keeping your body warm. The body cannot maintain it's own temperature in water cooler than 33 degrees, so even in the tropics some kind of suit is needed.

This article explores the different options available in the current market. As with anything to do with diving, it pays to buy the best you can afford. There are cheap suits on the market made from synthetic material, which simply don't offer the same thermal properties as neoprene. There are also suits available, which are aimed at the windsurfer, surfer or snorkellor - none of these are really suitable for diving.

Thickness
Generally, suits come in three thicknesses - 3MM, 5MM and 7MM, and it should be obvious that the thicker the wetsuit, the better insulation it offers. 3MM suits are perfect for the tropics in summer, and 7MM suits for the UK in summer, for example.

As well as the different thicknesses, there are four styles of wetsuit to choose from:

Style

Shorty - this is really only suitable for warm water diving and will have short legs and arms

Full Length - a standard suit with full length arms and legs

Layer Suit - this is a suit with at least two layers. for example a sleeveless shorty, with thinner, full suit on top. Very much in vogue at the moment.

Semi-dry - this type of suit has seals at the neck, arms and feet, and although not a dry suit, will keep water ingress to a minimum, and avoid flushing water through itself

Fitting

A wetsuit needs to fit snugly to do it's job - a baggy suit will pool water and allow cold water to continuously flush through. Common sense needs to be used though, it should still allow you to breathe! Pay attention to the zip fastener - it's this that will cause the most problems as the suit gets older. Plastic zips won't corrode, but metal zips are stronger.

Maintenance

Wash the suit throughly in cold, fresh water after every dive and allow it to dry, preferably out of direct sunlight. There are specialist shampoos available, but they aren't really necessary. Occasionally lubricate the zip with a very thin smear of petroleum jelly, and store the suit out of the sun, ideally on a hanger. If you need to fold the wetsuit, be careful that it isn't folded against the zip fastener as this can damage the neoprene. Over time neoprene will lost the natural "bubbles" in the material and the suit should be replaced with a new one.