pontoon

A pontoon is a buoyant structure used to provide flotation for a vessel, platform, or other load. In common usage the term most often refers to a pontoon boat, a shallow-draft vessel that uses multiple buoyant pontoons, or tubes, arranged beneath a flat deck. Pontoon boats are widely used for recreational boating on lakes and rivers and can be equipped for cruising, fishing, or social gatherings.

Pontoons are typically made of aluminum, steel, fiberglass, or composite materials. They are sealed chambers that trap air to provide buoyancy. A deck or cabin is mounted on top, forming a pontoon boat hull. The number and size of pontoons, the deck layout, engine power, and optional ballast determine stability, draft, load capacity, and speed.

Other uses of pontoons include floating bridges that rely on a system of pontoons to support a roadway across water, allowing temporary or permanent crossings. Seaplanes and floatplanes use pontoon floats to enable takeoff and landing on water. In civil and military engineering, pontoon bridges have been employed for rapid river crossings and disaster response situations.

Maintenance involves regular inspection for corrosion, leaks, and damage to seals and joints, as well as checks of buoyancy and flotation capacity. Proper storage and protection from impacts can extend the life of pontoons and connected equipment.