We were snorkeling off at Beehive Cove, which is off of Great Lamshur Bay, St. John, USVI, and saw these objects fixed underwater, obviously part of someone’s experiments. The plates could be to determine settlement rates of sessile reef invertebrates, like corals, sponges, stuff like that. A friend in grad school with Anne in Galveston did a similar experiment to determine the settlement rate of barnacles, something that’s close to cruiser’s minds, if not exactly near and dear to their hearts. The tubes could be sediment traps to determine the rate or extend of sediment deposit. Then again, I could be completely wrong and they could be something else entirely!