The Hughes Hercules was the largest seaplane ever built. It was made of wood and took to the air for the first and only time in 1947. It had a wingspan of 94.49 m (312 ft) and was powered by eight 3,000 hp engines.

A seaplane is an airplane that can land on and take off from water. The first practical seaplane was built in the USA by Glen Curtiss in 1911. There are type main types of seaplane. Floatplanes have large floats that support the fuselage above the water. Flying boats float on their boat-shaped hulls, with small floats supporting the wings. In the 1930s flying boats carried more passengers than any other type of aircraft. Some floatplanes and flying boats are fitted with wheels so that they can take off and land on ground as well as water; such aircraft are called amphibians.