Gliding over water can be done in a variety of ways. Skiing is a popular activity that involves sliding on two skis over the surface of the water. Sailing is another way to glide over water, using a sailboat to catch the wind and propel the boat forward. Skimming is a third way to move across the water, using a flat object such as a stone or a board to SKIM the surface of the water. All three activities provide a unique way to enjoy the water and the outdoors.