Black and white with a very tall first dorsal fin and a long trailing second one, swimming a repeated figure of eight under a ledge. Juveniles have a dorsal fin longer than the body.
To about 27 cm, black and white, with a first dorsal fin standing up like a banner and a long trailing second dorsal, and white spots on the tail and rear fins. The juvenile carries this further: the dorsal fin is longer than the whole body and the fish is almost all fin. It is separated from the high-hat, which shares the shape, by the spots — the high-hat is striped and has none.
It lives under a ledge or in a small cave, swimming a slow repeated figure of eight in the same few square metres, and it is nocturnal, feeding out on the sand after dark. That looping is what makes it photographable and frustrating in the same measure: the fish will pass the same point every fifteen seconds and will not hold still at any of them. Frame the loop, prefocus, and wait rather than following it.
Ratings are per location: 1 means found on most dives that look for it, 5 means a handful of records. Where enough dives have been logged the figure is calculated from them; otherwise it is an editorial estimate, and says so. We publish habitat and destination, not the dive site.