Manta rays are frequently spotted at St. John in Maho and Francis Bay. Pelagic, sure, but we had one swim between Sweet Christine and the beach at Francis and she was barely waist deep in the water. It looked like a very large black magic carpet going by. They're more like 8-12 footers.
http://newsofstjohn.com/2013/04/12/mad-about-manta-rays/https://www.youtube.com/watch?v=aqaEi4QsqJoThe pair of Mantas I saw at Brewers Bay were in the deeper water between the two points of the bay. They swam by and it was rather a surprise. Then they came back for another pass and it was a great experience. They looked very large, but I did not have reference, so I would just say that they were bigger than 12 feet. It was summer time in the mid 1990s and the water was super clear. Great memory.
Cheers, RickG
