As DelMarrey says, it's a power boat
thing. On sailboats, have always seen the strainer facing aft where it won't pick up debris as easily and speed creating a vacuum is a non issue. Recently had a yard that almost exclusively does power boats change the head
intake. The put the stainer facing forward. When I questioned the worker about it, he said it needed to be forward to force water into the strainer at power boat
speeds. Had already invested money
in that haul out
so just left it facing forward.