watersportsinfo.net

Under water

• Scuba diving is swimming under water using a (self contained) breathing apparatus
• Free-diving is the aim to maximize the depth dived using no breathing apparatus
• Underwater rugby is rugby played under water with a ball that has been rendered neutrally buoyant. Breathing is done through a snorkel, and tackling is only allowed if you have the ball or are tackling the one holding it.
• Underwater hockey is hockey played under water with short wooden curved sticks and a heavy puck. Players wear diving masks, snorkels, and fins, and must surface to breathe while team mates continue the game on the pool bottom.
• Underwater photography is photography done under water. Numerous contests worldwide are arranged every year. The digital cameras have revolutionized how many divers participate.

Source:

http://en.wikipedia.org/wiki/List_of_water_sports