I think that you mean where a river meets the ocean? Since the ocean and the sea are the same thing. It is called an estuary.
boy meets world
estuary
The Pacific Ocean
Pacific
His name in the show was Mr.Feeny and his real name was William Daniels
silt
This is called the "mouth" of the river.A stretch of a river whose depth varies with the sea tides is called an estuary, and may contain brackish water or saltwater.
Pelargic creatures.
Florida
A teacher whose name we do not know.
John Lennon