Stock Photo - Seaplanes in Vancouver harbor. A seaplane is a powered fixed-wing aircraft capable of taking off and landing (alighting) on water. Seaplanes that can also take off and land on airfields are in a subclass called amphibian aircraft. Seaplanes and amphibians are usually divided into two categories based on their technological characteristics: floatplanes and flying boats; the latter are generally far larger and can carry far more. These aircraft were sometimes called hydroplanes, but currently, this term applies instead to motor-powered watercraft that use the technique of hydrodynamic lift to levitate their main hull above the water when running at speed.