is that few people recognize it as a distress signal. At least, that's what the Boat U.S. experiment discovered, if I recall correctly.
Me . . I think I;d keep a barrel of tar on board so I could make a nice big flame. THAT would get attention (and it's the oldest distress signal in the book.
As for the black and orange distress flag -- visible form how many yards? And does it look any different from a beach towel?
Rant over . . . for now