Water skiing is very easy once you are on top of the water, but getting up is, for some, very difficult. If you just hop in the water with skis and a rope attached to a boat, most likely you won't get anywhere. You need a little bit of training first. Let's start with the physics of it. There are three major factors that go into the lift off: gravity, water, and tow. First, gravity, which deals with the force pulling you downward, or, your weight, and with the boat pulling you forward, you will also be moving forward. The water is the shape and angles of the wake from the boat, and also the shape of your skis, including the fins and length. The tow is very important. The tow is the acceleration and speed of the boat.
Before, you hop in the water, make sure the driver knows how to tow skiers. It is normally very simple. They will need to speed up quickly or "gun it" until you are up and out of the water. Then, the skier will signal to speed up or slow down with a thumbs up or down. But, let's move backward a bit. When you are in the water, you need to sit leaned back with your knees bent at 90 degrees. Put the rope between the skis and keep about 2 inches of ski out of the water. Yell "ready" for the boat to start. Keep your knees firmly bent until you are halfway up, then push against the water as you extend your knees. If you are following these instructions you will get up!
When you are done swing your hand inward across your neck as if to say "cut". Make sure the driver knows the signals. Then, as the boat slows, let go of the rope, take off you skis and swim to the boat. Congratulations! You now know how to ski!