30 to 40ft (9-12m)
Nautilus Reef is a combination of two shallow reefs set upon old lava rock beds. It was named after the glass bottom boat Nautilus that toured the area, but has since been relocated to Guam.
Lots of reef fish here including triggerfish, boxfish, goatfish, tangs. Also sightings of manta rays, stingrays, tiger sharks and grey reef sharks are possible at the outer edges of the reef. Monk seals have been seen here too.