Night dive with manta rays. This is an absolutely awesome experience. Divers gather on the bottom and shine bright lights which attract plankton. Plankton attracts mantas. During my dive, 8 mantas showed up, including the 3 largest ones swimming in these waters. Females are much bigger than males. The largest female of all is "Big Bertha" with a wingspan of 16 feet. She's estimated to be between 60 and 70 years of age and she's still breeding. Big Bertha took a liking to my video light and repeatedly grazed my head as she swooped in over me.