A watercraft speeds through the water.
Some boats are small.
Speeding through the water doesn't imply it is small.
exists e1 x1 x2.(n_water(x2) & through(e1,x2) & Actor(e1,x1) & v_speed(e1) & n_watercraft(x1))
exists s1 x1.(Theme(s1,x1) & a_small(s1) & n_boat(x1))