Can you float in the water? Have you floated in a rubber raft? The raft is filled with air. Some people use an animal skin filled with air to float in the water. Others float in boats or on rafts made of wood.

To move around while you are floating in the water you must move your arms. On a raft or in a boat you must use an oar or a stick to steer or move.

An easy way to move around in the water is to use a sail. A sail is a piece of cloth on a pole (mast) in a boat. The wind fills the sail with air. The sailboat moves forward.

There must be wind to fill the sail and push the boat. A sail with three corners (triangle) will make the boat go fast. A square sail will make a boat go too.