
Grey Reef Shark — see destinations where it is seen
Carcharhinus amblyrhynchos
Micronesia · Micronesia
Documented presence, never a guaranteed sighting.

Carcharhinus amblyrhynchos

Triaenodon obesus
Wreck Diver specialty recommended
A former refrigerated cargo ship requisitioned as an armed aircraft ferry, sunk during Operation Hailstone (Feb 1944) — Truk Lagoon's most popular and photographed wreck. At least nine disassembled fighter-plane fuselages sit in a forward hold, alongside an enterable engine room. The upper structure (9-18m) is reachable by intermediate divers; the hull rests at 30-34m. Wreck Diver certification is recommended, not required, for interior penetration. Land-based day-boat diving is real and common, but liveaboards are the dominant way to dive Chuuk's ~40-mile-wide lagoon efficiently (up to 5 dives/day vs. 2 from shore).
Wreck Diver specialty recommended
Known as the "Million Dollar Wreck" for its still-intact war cargo: three Type 95 Ha-Go tanks on deck, plus trucks, aircraft engines, and munitions in the holds. One of Truk Lagoon's deepest wrecks — deck around 50m, hull down to roughly 60-64m — genuinely requiring technical/trimix training and decompression-planned diving, a sharp contrast to Fujikawa Maru's intermediate-accessible upper decks. Liveaboard is the practical way to reach it.
Documented best months
In season this month: Grey Reef Shark, Whitetip Reef Shark
Water temperature: NOAA OISST satellite sea-surface normals (2020–2024, typical range for the month). It can be cooler at depth or below a thermocline — check with your operator for exposure protection.
Wreck Diver specialty
Sites concerned (2/2): Fujikawa Maru, San Francisco Maru
A required level is a floor: a more experienced diver always qualifies.