4. Motion with reference to direction
[Verbs] plunge, dip, souse, duck; dive, plump; take a plunge, take a header; make a plunge; bathe (water) [more].
submerge, submerse; immerse; douse, sink, engulf, send to the bottom.
get out of one's depth; go to the bottom, go down like a stone, drop like a lead balloon; founder, welter, wallow.