Water skiing (also waterskiing or water-skiing) is a surface water sport in which an individual is pulled behind a boat or a cable ski installation over a body of water, skimming the surface on two skis or one ski. The sport requires sufficient area on a stretch of water, one or two skis, a tow boat with tow rope, two or three people (depending on local boating laws), and a personal flotation device. In addition, the skier must have adequate upper and lower body strength, muscular endurance, and good balance. There are water ski participants around the world, in Asia and Australia, Europe, Africa, and the Americas. In the United States alone, there are approximately 11 million water skiers and over 900 sanctioned water ski competitions every year. Australia boasts 1.3 million water skiers. There are many options for recreational or competitive water skiers. These include speed skiing, trick skiing, show skiing, slaloming, jumping, barefoot skiing and wakeski. Similar, related sports are wakeboarding, kneeboarding, discing, tubing, and sit-down hydrofoil. Basic technique Water skiers can start their ski set in one of two ways: wet is the most common, but dry is possible. Water skiing typically begins with a deep-water start. The skier enters the water with their skis on or they jump in without the skis on their feet, have the skis floated to them, and put them on while in the water. Most times it can be easier to put the skis on when they are wet. Once the skier has their skis on they will be thrown a tow rope from the boat, which they position between their skis or, if on only one ski, to the left if right foot forward and to the right if left foot forward. In the deep-water start, the skier crouches down in the water while holding onto the ski rope; they are in a cannonball position with their legs tucked into their chest, with skis pointing towards the sky and approximately of the ski out of the water. The skier can also perform a "dry start" by standing on the shore or a pier; however, this type of entry is recommended for professionals only. When the skier is ready (usually acknowledged by them yelling "in gear,": followed by "hit it"), the driver accelerates the boat. As the boat accelerates and takes up the slack on the rope, the skier allows the