People are gathered on a platform in water for a ceremony.
The people are on the platform for a wedding with a pirate concept.
You can not infer there is a pirate concept.
exists e1 x1 x2 x3 x4.(for(e1,x4) & n_ceremony(x4) & in(e1,x3) & n_water(x3) & on(e1,x2) & n_platform(x2) & Theme(e1,x1) & v_gather(e1) & n_people(x1))
exists p1 x1 x2.(n_platform(x2) & n_people(x1) & exists s1 x3 x4.(on(x1,x2) & for(x2,x3) & with(x3,x4) & n_concept(x4) & a_pirate(s1) & Theme(s1,x4) & n_wedding(x3)))