Here's one I shot several years ago in Honolulu at the Dragon Boat Races.
Al, the light stuff is silt & sand. The channel into the harbor is large and well marked. I was out near the Royal Albatross Center when I took that shot. Here's the satellite image.Hey Phil,
Any idea of the different water colors? Not that I'm planning on anchoring there in this lifetime, but if that light stuff is shallow it looks a bit treacherous.