Definition
Airplanes designed to take off from and land on water, equipped with floats or a hull instead of (or in addition to) standard landing gear. Seaplanes include floatplanes, which sit on pontoon-style floats, and flying boats, whose fuselage itself acts as the hull resting on the water.
Plain English
Airplanes built to operate from water rather than a runway. They either sit on floats or have a boat-shaped body that lets them land on lakes, rivers, or the sea.
Context Anchor
Seen when aircraft types and pilot privileges are discussed, especially where training materials separate landplanes from aircraft that operate on water.
Derivation
From 'sea' (water) and 'plane' (short for aeroplane). The name simply marks the airplane as one that operates from water.
Why Pilots Care
Seaplane operations involve unique handling, such as water rudders and wave considerations, and require specific ratings or endorsements.
Intuition Check
Do not assume “seaplane” means an airplane used only on the ocean. In aviation, seaplanes may operate on lakes, rivers, bays, or other suitable water areas.
Example Sentence 1
Seaplanes are common in Alaska and northern Canada, where lakes often serve as the only practical landing sites.
Example Sentence 2
Light-sport seaplanes must meet specific FAA design and performance standards for water operations.