shelf
The portion of the land mass that extends into the ocean is called the coastline or shoreline.
A Gulf
A Gulf
continental shelf peninsula
The portion of the land mass that extends into the ocean is called a "coastline." It is the boundary where the land meets the sea, and it can vary in length and shape due to factors like erosion and tectonic activity.
The land under an ocean at the edge of a continent is called the continental shelf. This is the shallow submerged portion of a continent that extends from the shoreline to the continental slope.
shelf
That would be called a Sound.
A sea a portion of ocean that is enclosed or partly enclosed by land
A portion of ocean that is enclosed or partly enclosed by land? ✓ sea
A Gulf
Peninsula.