What is a Wetsuit?
A Wetsuit is a garment, made of a light material such as neoprene, the wetsuit actually does let a little water into the suit. The water is allowed to circulate between the skin of the diver and the outside suit layer. As a result, the trapped water is gradually warmed up to near body temperature and can help keep the diver comfortable during the diving process. The suit layer helps insulate the warmed water next to the body from the outside water. A wetsuits purpose is to provide thermal insulation, abrasion resistance and buoyancy.
Suits range from a thin (1 mm or less) "shortie", covering just the torso, to a full 8 mm semi-dry, usually complemented by neoprene boots, gloves and hood. Wetsuits come in different thicknesses depending on the conditions for which it is intended. The thicker the suit, the warmer it will keep the wearer.
Wetsuits are made in a variety of thicknesses of neoprene. The thicker the neoprene, the warmer you'll stay and the more flexibility you lose. One thing to keep in mind is because neoprene contains air bubbles, the deeper you descend in the water, the thinner your suit will become. If you're comfortable on the surface, you may find yourself feeling cold at depth if your suit isn't thick enough.
2-3mm-thick neoprene is ideal for warm water diving and snorkeling. This thickness slightly insulates the diver from the water and protects the diver from sharp or injury-causing objects at depth. This option is also a great way for snorkelers to protect themselves from the sun. If you tend to feel warm easily, this is probably the best thickness for you if you plan on being in warm or slightly cool water.
5mm-thick neoprene is ideal for warm water divers and snorkelers who tend to feel cold easily. This thick- ness insulates the diver better than a 2 or 3-mm suit; the tradeoff is that the diver's range of motion is slightly reduced because of the thicker material.
6mm-thick neoprene is cold-water gear. It offers the greatest amount of warmth and the least amount of flexibility. The 7mm thickness offers a large amount of air bubbles to trap the heat, which is important, especially as your descend and the water's pressure compresses your suit.
Because wetsuits offer significant protection from jellyfish, coral ,sunburn and other hazards, many divers opt to wear a thin suit which provides minimal insulation (often called a "bodysuit") even when the water is warm enough to comfortably forego insulating garments. A thick suit is stiff, so mobility is restricted; at a certain thickness the suit would become impractical, which is why drysuits must be worn in particularly cold environments.
A wetsuit is normally described in terms of its thickness. For instance, a wetsuit with a torso thickness of 5 mm and a limb thickness of 3 mm will be described as a "5/3". With new technologies the neoprene is getting more flexible. Modern 4/3 wetsuits, for instance, may feel as flexible as a 3/2 of only a few years ago. Some suits have extra layers added for key areas such as the lower back.
"When divIng, the cold is your worst enemy!"
In addition to your one-piece, don’t hesitate to put on more layers of neoprene to avoid having a suit for each condition, several products can be added to your suit depending on the temperature.
Using hoods: in the thermal balance of the human body, the heat loss over the head is at least 20% of the whole balance. Thus, for the sake of thermal protection of the diver, wearing a well-fitting hood is good practice, even at fairly moderate water temperatures.
While the wetsuit does need to be form fitting, it is important that it not be too tight OR too loose. This allows the warmed water to remain in place for the duration of the dive, especially important in recreational scuba diving, as the material will compress somewhat as the diver goes deeper. Too loose and water will constanly move in and out of the suit preventing the water from being warmed.