Seaplanes are airplanes that can land on and take off from water.
Seaplanes are often used in places where there are a lot of water and not many regular airports.
Examples:
The seaplane landed on the lake.
We saw two seaplanes taking off from the ocean.
The seaplanes are very loud when they fly over the beach.
The seaplane pilot waved to us as he flew by.
I want to ride in a seaplane and land on the river.
The seaplane looks like a regular airplane, but it can land on water.