Definition
An airplane designed to take off from and land on water, equipped with either floats (a floatplane) or a watertight hull (a flying boat) in place of, or in addition to, conventional landing gear.
Plain English
An airplane built to operate off water instead of, or in addition to, a runway.
Context Anchor
You will see this term in seaplane training, water operations, aircraft category and class discussions, and chapters covering takeoffs, landings, taxiing, docking, and beaching on water.
Derivation
A straightforward compound of 'sea' and 'plane.' Worth noting: 'sea' here is used loosely — seaplanes routinely operate from lakes and rivers, not just the sea.
Why Pilots Care
Seaplane operations require their own FAA rating (ASES or AMES) because water handling, takeoff, and landing techniques differ significantly from land operations.
Intuition Check
A seaplane isn't only for the sea — the term covers any airplane that operates from water, including lakes and rivers. Also, 'seaplane' is the broad category; 'floatplane' and 'flying boat' are the two main types within it.
Example Sentence 1
He earned his seaplane rating on a small lake in Maine, learning to read the water surface before each landing.
Example Sentence 2
During the lesson the instructor demonstrated how to align the seaplane with the wind for a safe water landing.