Two inflatable boats at Horsea Island, England

An inflatable boat is a light-weight but high performance and high capacity boat constructed with flexible tubes at the gunwale. Often they are designed to be highly portable by being deflated and packed into a small volume allowing them to be used as liferafts for boats or aircraft or simply so that they can easily be transported to water.

The boat's floor is made of steel, wood or aluminium sheets. The tubes are made of rubberised, synthetic sheet and provide a large amount of light-weight and secure buoyancy. The tubes are often constructed in separate sections, each with a valve to add or remove air, to reduce the effect of a puncture, meaning that should one section puncture it is quite possible to repair it while still underway, and the patched area will probably be tougher than the original.

Some inflatable boats have an inflated keel to create a "groove" along the line of the hull improving the hull's wave cutting and turning performance. Due to the weight, it is very easy to make an inflatable boat hydoplaning, thus making it faster than the engine would allow when the hull is operating in displacemement mode. The rigid-hulled inflatable boat is a development of the inflatable boat.

Due to the speed, the portability and the weight, inflatable boats are used extensively in tending operations in port and at sea, recreational water skiing, commercial fishing, and in the military, for example, with US Navy SEALS. The size-to-strength ratio of these vessels make them exceptionally portable and valuable in covert operations.

Inflatables are often between 2 and 7 metres (6 to 21 feet) long and are propelled by outboard motors of 5 to 80 horsepower (4 to 60 kW). They are commonly used as rescue craft, dive boats or tenders for larger boats and ships or for racing. Inflatables up to 6 metres in length can easily be towed on trailers on the road.