A pontoon is a flat-bottomed boat or the floats used to support a structure on water. It may be simply constructed from closed cylinders such as pipes or barrels or fabricated as boxes from metal or concrete. These may be used to support a simple platform, creating a raft. A raft supporting a house-like structure is one form of houseboat. The basic design is usually implemented as a simple catamaran or, with three rows of floats, a trimaran. A fixed platform can be used as a dock.
Pontoon boats generally are low cost and less expensive to insure than a normal boat, even when equipped with engines of over 200hp. They are also almost foolproof to operate and cannot be sunk. Their shallow draft also reduces damage from submerge collisions and being run aground. As such, they are the most popular vessel style for rental operations, on US freshwater ways. They also offer the largest value in terms of capacity to price.