There are four length classifications of boats:
1. Canoe: A canoe is a small, narrow vessel that is propelled by someone using a paddle. It is typically used for recreation or transportation on calm waters.
2. Kayak: A kayak is a small, narrow vessel that is propelled by someone using a double-bladed paddle. It is typically used for recreation or transportation on calm waters.
3. Sailboat: A sailboat is a larger vessel that is propelled by the wind in its sails. It can be used for recreation or transportation on both calm and open waters.
4. Motorboat: A motorboat is a vessel that is powered by an engine. It can be used for recreation or transportation on both calm and open waters.