Someone in astronaut gear is being submerged underwater.
Someone in astronaut gear is being put underwater.
Being submerged underwater only can mean one is being put there.
exists e1 s1 x1 x2 x3.(Recipient(e1,x3) & Theme(e1,x1) & v_submerge(e1) & n_underwater(x3) & in(x1,x2) & n_gear(x2) & a_astronaut(s1) & Theme(s1,x2) & n_person(x1))
exists e1 s1 x1 x2 x3.(Time(e1,x3) & n_underwater(x3) & Theme(e1,x1) & v_put(e1) & in(x1,x2) & n_gear(x2) & a_astronaut(s1) & Theme(s1,x2) & n_person(x1))