boat to pull them out of the water by applying some muscle strength to get into an upright body position. By leaning back and keeping the legs slightly bent, the skis will eventually plane out and the skier will start to glide over the water. The skier turns by shifting weight left or right. The skier's body weight should be balanced between the balls of the feet and the heels. While being towed, the skier's arms should be relaxed but still fully extended so as to reduce stress on the arms. The handle can be held vertically or horizontally, depending on whichever position is more comfortable for the skier. In addition to the driver and the skier, a third person known as the spotter or the observer should be present. The spotter's job is to watch the skier and inform the driver if the skier falls. The spotter usually sits in a chair on the boat facing backwards to see the skier. The skier and the boat's occupants communicate using hand signals (see the Safety section below). Equipment Water Water skiing can take place on any type of water – such as a river, lake, or ocean – but calmer waters are ideal for recreational skiing. There should be a skiing space and the water should be at least deep. There must be enough space for the water skier to safely "get up", or successfully be in the upright skiing position. Skiers and their boat drivers must also have sufficient room to avoid hazards. Skis Younger skiers generally start out on children's skis, which consist of two skis tied together at their back and front. These connections mean that less strength is necessary for the child to keep the skis together. Sometimes these skis can come with a handle to help balance the skier as well. Children's skis are short – usually long – reflecting the skier's smaller size. Once a person is strong enough to hold the skis together themselves there are various options depending upon their skill level and weight. Water skiers can use two skis (one on each foot, also called "combo skiing") or one ski (dominant foot in front of the other foot, also called "slalom skiing"). Generally the heavier the person, the bigger the skis will be. Length will also vary based on the type of water skiing being performed; jump skis, for example, are