Oceans are seawater throughout, not only on the surface.
No, salty water has higher density, that's why it's easier to stay close to surface in sea or ocean.
because the ocean sponge gets bigger by absobing the sea water to stay alive
A surface current is found at the surface of the ocean caused by wind patterns.
A seamount is a mountain rising from the ocean seafloor that does not reach to the water's surface (sea level), and thus is not an island.
Oceans are continuous bodies of water that cover most the Earth's surface, A sea is a region of water withing an ocean, partly enclosed by land. Such as the North Sea. A sea can be a large body of either fresh or salt water completely enclosed by land. Such as the Caspian Sea
The height of the surface of the ocean is referred to as sea level.
The word 'sea' refers to the water that covers the greater part of the Earth's surface, one of the smallest areas of an ocean
The terms sea and ocean are usually considered to be synonymous. A sea is a sometimes defined as a division of an ocean, or a large body of salt water partially or entirely enclosed by land. An ocean is the body of the salt water covering 71% of the earth's surface, or any of the major divisions of that body of water which are called the Pacific, Atlantic, Indian, and Arctic Oceans.
Saltwater, but it is much less salty than the open ocean at least on the surface.
They use ballast tanks to contain sea water or air to control their depth
IT'S called ocean currents or just called currents.
A seamount is a mountain rising from the ocean seafloor that does not reach to the water's surface (sea level), and thus is not an island.