nose-dive(о рельефе местности, подводной топографии и т.п. • I swam out from the small floating jetty which was there in those days. A hundred yards or so from the jetty, the floor of the bay suddenly nose-dives into deep water. I had just passed this point and was about 10 or 15 feet below the surface, but was now in deep water and was thinking that I should turn and go back when I saw an object in front of me. (mysteriousuniverse.org) -- дно бухты внезапно обрывается и начинается глубоководьеART Vancouver)
