The narrow channel of sea which separates two landmasses is known as Strait
This is a strait
A strait is a narrow channel connecting two bodies of water.
A strait is the narrow channel of water between two land masses.
A narrow channel near the island of Salamis
straight, strait
Strait of Hormuz
a straight is narrow body of water, and a channel is a wider body of water.
Strait -- channel of water straight -- not crooked
straight, strait
a channel
They're both narrow and longish bodies of water.