Finding the right wetsuit for you is vital. There are a number of things to bear in mind when you're making your choice but, in the end, the key to the ideal wetsuit for you is fit. If it doesn't fit well, you won't perform at your best. Simple as that.
The suit should feel very snug but it should also be flexible and allow in a small amount of water, which, when heated by your body, will help to keep you warm in the open water.
Take your time when trying on suits; the one for you should not sag or chafe anywhere when you move. Sagging points will allow water to gather as you swim, which will slow you down, and no one needs to be told how uncomfortable chafing can be. Be especially careful to ensure the neck area is free from anything that will catch your skin or restrict your movement.
When you put on the suit, check that the sleeves end just before the point where your wrist bone juts out; if the sleeves are lower than this, more water will be let in.
Wetsuits are made from neoprene, which is designed to improve your buoyancy and insulate you. In a good suit, the neoprene around the shoulders should be thinner than elsewhere, to allow maximum movement, and the chest panel, which provides buoyancy, should be at least four millimetres thick.
Finally, the best suits have seams that are sewn, glued and taped.