Harmless most of the year, and genuinely dangerous over a nest.
The largest triggerfish in the region, to about 75 cm, olive to grey-green with each scale dark-edged so the body reads as a coarse mesh, a broad dark moustache above the mouth and yellow-tinged fin margins. The teeth are heavy and chisel-like and are used to crush urchins, molluscs and coral; a feeding fish turns rocks and blows water at the sediment, and smaller wrasses follow it for what it exposes.
Its reputation is entirely about nesting. The female excavates a shallow crater in rubble, lays there, and defends the water above it — a roughly conical territory that widens towards the surface. Swimming up to escape moves the diver further into the defended space rather than out of it, which is why the standard advice is to leave horizontally, keeping fins between the fish and yourself. Outside the nesting period it is indifferent to divers. Recorded from the shallows to about 40 m.
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.