It looks like the crane's hook is right on the waterline, so maybe it was going tug fishing?
Impressive aviation find on not at all aviation website.... kudos to you Batfink:
I'm a conscientious man... when I throw rocks at seabirds I leave no tern unstoned. (Ogden Nash)
Et nom de dieu! C'est triste Orly la dimanche (Jacques Brel)