Physics of Water Skiing
One of my favorite things to do during the summer is water skiing. I don't go very often, but when I do, I love the satisfaction of getting up out of the water. In order to get up, you have to point your skis upward out of the water. By doing so, the skis are able to apply a force perpendicular to the direction of the velocity of the boat as the boat accelerates in the forward direction. This perpendicular force prevents the skier from face planting in the water. Then, you must tilt your skis to a lesser degree (as measured from the horizontal) in order to be pulled out of the water. By tilting your skis, the water applies a force, which has a component in the upward direction. This upward force pushes your skis upward until they are above the water level. The skis will remain afloat as long as the normal force to the skier, which is applied by the water, is equal to the downward force of gravity on the skier. Additionally, in order to avoid faceplanting in the water, the skier must recognize that as the boat accelerates in the forward direction, it will pull him/her forward. The skier then must apply an equal and opposite force to counter the force of the boat.