A scuba diving suit is a piece of garment worn by divers to protect themselves against the harmful effects they are exposed to underwater.
Dive suits are usually made from special neoprene material that allows a thin layer of water or air to penetrate among the layers of the material. The film of water or the layer of air is quickly warmed up by the body of the diver and the gas bubbles in the neoprene retain that heat, providing thermal protection to the wearer. The neoprene used in the suits is also very strong and durable, providing protection against cuts and abrasions.
There are three basic types of diving suits:
Wetsuits – used not only by divers, but by surfers and other water sports enthusiasts as well, these relatively thin and elastic suits are made from foamed neoprene and they are used in warm to moderately cold waters;
Layered systems – these suits have replaced semi-dry suits and they feature a layered design that provide maximum protection in cold water;
Dry suits – these suits work by trapping air, not water, inside the material they are made from. Being designed to keep divers warm in almost-freezing waters, dry suits are usually available only in full-length versions.
There are a number of factors that will determine your final choice:
The dive location – the temperature of the waters you will be diving in will determine the thickness of the suit. If you are planning to dive in temperatures above 29 degrees C (84 F), a 2 mm thick suit will work just perfectly; choose a 3 mm suit for temperatures ranging between 21-28°C (69-82 F), such as the Caribbean, but go for 5 mm thick material for colder waters ranging between 16-20°C (60-68 F) and for 6.5 mm or dry suits for waters that are colder;
Suit style – you can choose to get a full suit that comes will full-length legs and arms to offer complete protection against the water and the sun or a shortie-style suit that covers only the body and is therefore more suitable for warm waters; you can buy one-piece and two-piece suits, and you can choose between hooded models (usually the choice of cold water divers) and hoodless ones, too;
Finally, getting the best fit is of utmost importance. Your suit must fit perfectly, without being too tight or too baggy. If the scuba diving suit is too tight, it will not allow you to move properly, while baggy suits will let too much water in, failing to give you the thermal protection that you need.