英和和英

the ocean floor

the profound depths of the sea

deep-ocean water

the depths of the ocean

the floor of the sea; the land at the bottom of the sea

a submarine geographical feature, called deep

a geographical feature of the seabed called a sea valley

a geographical feature of the sea floor called a ocean basin

a diver in the deeper parts of the sea

an elevation of the ocean floor, called ridge

a geographical feature of the sea bed called {'sea hill'}

a geographical feature of the sea floor, that is a gently sloping submarine ridge, called 'kaibo'

a submarine volcano

a geographical feature of the ocean floor called a plateau

the depths of the ocean

an oil field under the seabed

a submarine mine

to go to the bottom―sink into the depths of the sea

anchors aweigh

deep-sea exploration

a deep‐sea diver

a place where the bottom of the sea rose called 'Gyoshou'

an offshore oil field

the bottom of a sea or ocean

a submarine cable

（人なら）to sink beneath the waves―（船なら）―go down―go to the bottom

a submarine telegram

to sink something in the sea

submarine telegraph