Grauer Riffhai

Identification

Grey reef sharks are medium-sized requiem sharks reaching about 2.5 meters. The most reliable field mark is the solid black margin along the entire trailing edge of the caudal (tail) fin — no other reef shark has this. The body is slate grey on the back fading to white below.

Distribution & Habitat

Grey reefs are widespread in the Indo-Pacific, from the Red Sea east to French Polynesia. They favor outer reef slopes, atoll passes with strong currents, and deep channels between 20 and 60 meters, though they descend much deeper on occasion.

Behavior

Grey reefs form daytime aggregations in currents, where they face into the flow and let oxygenated water pass over their gills. This behavior has made them iconic dive encounters at sites like Blue Corner (Palau), Fakarava South Pass (French Polynesia), and the Maldivian atolls. When threatened, they perform a distinctive hunched display: arched back, pectoral fins pointed down, head swinging side to side. If you see this, back off slowly — the next step is a bite.

Where to See Them

Fakarava South Pass hosts a legendary aggregation of 500+ grey reef sharks, best seen in July during grouper spawning. Blue Corner in Palau and the Maldivian channels offer year-round encounters. Use a reef hook in current, keep low, and never chase.