We went with Capt. Nancy on the Sunset Manta Ray cruise and snorkel. It was almost a surreal experience. The manta's circled and swooped all around us, even rubbing against us at times. The diving lights created a cathedral of light from below and with our torches shining from above, we created a light show on these prehistoric looking animals. They approached with their mouths open while feeding on the plankton bloom generated by the lights. It was like being in a Star Trek episode!
Capt. Nancy, Capt Bob, Pete and Zoe were experienced and competent. If you are nervous about snorkeling at night, don't be. It was an amazing experience.
A wet suit is required and are easily rented. If you tend toward getting cold, a thicker mi suit is recommended.