The sunlit shallow coral reefs are easily accessed using snorkels or ordinary scuba gear. The Twilight Zone of coral reefs, from 50 to 150 metres, is scarcely explored. Conventional diving gear at the latter depths permits too little 'bottom' time and is unsafe. New state-of-the-art mixed-gas, rebreathing scuba gear permits safe and long dives to experienced "aquanauts" like Richard Pyle, The early samples from his dives reveal that as much as one third of the species are new to science.