Exposure Suit

• The exposure suit keeps the scuba diver warm in cold water. However, in addition to keeping a diver warm, it also offers protection from getting cut up on reefs and from sunburn. According to PADI (Professional Association of Diving Instructors), there are three kinds of exposure suits: bodysuits, wet suits and dry suits. Bodysuits are useful in tropical waters but offer very little insulation. Wet suits come in a variety of thicknesses and are used in both tropical and more temperate waters. They work by letting in a thin layer of water, which is then warmed to body temperature. Dry suits are used in cold water and do not allow any water in.
  
  

Tanks

• Tanks, also known as cylinders, hold compressed air that allows divers to breathe under water. Tanks today are made from either an aluminum or steel alloy. These tanks are rated for a pressure of 3000 PSI (pounds per square inch). Dive tanks come in a variety of sizes from 65 cubic feet to 100 cubic feet. The most common is 80 cubic feet. You can get an extra-large tank, 120 cubic feet, and a tiny six-cubic-feet tank, which is carried as a spare. The size of the tank you use depends on how much air you consume. Factors such as your size, lung capacity and fitness level affect your air consumption.
  
  

Bouyancy Controld Device and Weight Belt

• The BCD (buoyancy control device) holds your tank in place and uses air to control your buoyancy in the water. The BCD has bladders that you can inflate or deflate. To increase your buoyancy in the water, add air to your BCD using a low-pressure inflator/deflator. When you want to descend, deflate your BCD. Another way to control your buoyancy in the water is through the use of weights. Divers typically have a weight belt or weights that are integrated into the BCD. Weights will help you stay down under the water.
  
  

Regulator

• Your regulator is the device that allows you to breathe under water. It takes the high-pressure air in the tank and adjusts it to the correct pressure for breathing. The regulator also takes air from the tank and moves it to the BCD. The regulator has two sections called stages. The first stage connects directly to the tank, reduces air pressure and routes the air to the BCD and other devices. The second stage is the mouthpiece. In addition, divers should have an alternate second stage for emergencies.
  
  

Mask, Snorkel and Fins

• Because humans are unable to focus clearly under water, the dive mask creates an air pocket that allows divers to see clearly. The snorkel is the tube you breathe through on the water's surface so you don't have to use up air while swimming on the surface. Dive fins help divers to swim through the water using powerful leg muscles.