The term 'bottom of the ocean' refers to the deepest parts of the ocean, which are made up of several components. The KEEL is the structural base of a ship, and it is also used to refer to the lowest part of a boat or ship. The HULL is the outer shell of a boat or ship, and it is the part that is visible above the water. The seabed is the bottom of the ocean, and it is made up of sediment and rocks. Finally, the ABYSS is the deepest part of the ocean, and it is usually found at depths greater than 4, 000 meters.