A black dog jumps into the water to get a Frisbee while a boat sits in the back.
The dog runs very fast
A dog who jumps in the water to get a Frisbee is probably not running at all anymore and there is no reason to assume the dog runs very fast.  Dogs run at varying speeds depending on health, weight, age, enthusiasm and so on.
exists p1 s1 x1 x2 x3 x6.(n_back(x6) & n_water(x3) & a_topic(x1) & into(x1,x3) & Topic(x3,p1) & exists e1 p2 x4.(exists e2 x5.(in(e2,x6) & Actor(e2,x5) & v_sit(e2) & n_boat(x5)) & while(e1,p2) & Theme(e1,x4) & Actor(e1,x3) & v_get(e1) & n_frisbee(x4)) & n_jump(x1) & of(x1,x2) & n_dog(x2) & a_black(s1) & Theme(s1,x1))
exists e1 p1 x1.(n_dog(x1) & exists s1.(r_very(s1) & Theme(s1,x1) & a_fast(s1)) & Topic(e1,p1) & Actor(e1,x1) & v_run(e1))