Bubble coral, Plerogyra sinuosa     (Family Euphyllidae)

Location: Lighthouse Bommie, Ribbon Reef #10, Great Barrier Reef, Australia

Depth: 20.6 m

Equipment: Nikon D70 with Nikkor 18-55mm f/3.5-5.6G ED II in Ikelite housing and 2 x Ikelite DS125

Settings: @ 38mm, ISO200, 1/80s, f/16