Crossword Clue:

the bottom surface as of the ocean

AnswerCrossword Clue
OOZEMud at the bottom of the ocean.
INNERCOREThe Earth's may be as hot as the surface of the Sun
HULLBottom of the ocean?
KEELBottom of the ocean?
SEABEDBottom of the ocean
ATRIPJust clear of the ocean bottom