英和和英

the depths of the ocean

deep-ocean water

a diver in the deeper parts of the sea

the depths of the ocean

a submarine geographical feature, called deep

a geographical feature of the seabed called a sea valley

an oil field under the seabed

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

deep-sea exploration

a geographical feature of the sea floor called a ocean basin

an elevation of the ocean floor, called ridge

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

a geographical feature of the ocean floor called a plateau

a submarine volcano

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

a deep‐sea diver

a submarine mine

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