Many people are sitting on the edge of a rocky beach, watching others swim in the glistening water.
Swimmers are swimming by a rocking beach, as onlookers watch.
The people in sentence one are sitting on a rocky beach watching swimmers - so that means that the swimmers that are swimming, are swimming on a rocky beach, while being watched.
exists e3 e1 e2 s1 x1 x2 x3 x4 x5 x6 x7 x8.(n_water(x7) & of(x7,x8) & n_glistening(x8) & n_edge(x2) & on(e1,x2) & of(x2,x3) & in(e3,x7) & Theme(e3,x6) & Actor(e3,e2) & v_swim(e3) & (x3 = x6) & Theme(e2,x5) & Actor(e2,x4) & v_watch(e2) & -(x5 = x1) & n_person(x1) & n_person(x5) & n_thing(x4) & n_beach(x3) & a_rocky(s1) & Theme(s1,x3) & Actor(e1,x1) & v_sit(e1) & n_people(x1) & n_quantity(x1))
exists e2 e1 x1 x2 x3 x4 x5 x6.(as(e2,x6) & n_onlooker(x6) & Theme(e2,x5) & Actor(e2,x1) & v_watch(e2) & n_thing(x5) & by(e1,x3) & n_beach(x3) & of(x3,x4) & n_rocking(x4) & Actor(e1,x2) & v_swim(e1) & (x1 = x2) & n_swimmer(x1))