The man is on a ski boat in the water.
Last trip of the day for this water-sport enthusiast.
You cant infer that its the man's last trip based on his actions
exists p1 x1 x4.(n_water(x4) & n_man(x1) & exists x2 x3.(on(x1,x2) & in(x2,x4) & n_boat(x2) & of(x2,x3) & n_ski(x3)))
exists s1 s2 x1 x2 x3.(n_enthusiast(x3) & a_water-sport(s2) & Theme(s2,x3) & n_day(x2) & a_topic(x1) & for(x1,x3) & of(x1,x2) & n_trip(x1) & a_last(s1) & Theme(s1,x1))