People surfboarding and standing in the ocean.
People in the ocean.
People surfboarding and standing in the ocean is a rephrasing of people in the ocean.
exists e1 e2 x1 x2 x3.(n_ocean(x3) & in(e2,x3) & Actor(e2,x2) & v_stand(e2) & n_people(x2) & Actor(e1,x1) & v_surfboard(e1) & n_people(x1))
exists x1 x2.(n_ocean(x2) & a_topic(x1) & in(x1,x2) & n_people(x1))