I can't identify the flag behind the torpedo bulge. It seems to be pointy with a blue tip and white on the hoist end. Had the colours been the other way around it would have been the repeater flag "second substitute". Had it been tongue shaped and been yellow at the hoist it would have meant "5". Had it been tongue shaped with red at the hoist, white in the middle and blue tip it would have meant "3". If it has two points it would mean "A".
Edit: Someone tagged papa_(naval_flag), but that's clearly not it, so I'm removing that tag.
