Chuuk (Truk) Lagoon – Micronesia

Chuuk (Truk) Lagoon in the Federated States of Micronesia was the Imperial Japanese Navy's main base in the central Pacific. On 17–18 February 1944 US carrier aircraft sank around 40 ships and destroyed hundreds of aircraft in Operation Hailstone, and more ships were lost in raids in April 1944. Today the wrecks lie in warm, sheltered water around Dublon (Tonoas), Eten, Fefan, Uman and the Fourth Fleet anchorage, many encrusted with soft coral and still carrying tanks, trucks, aircraft parts, shells and everyday objects. Shallow sites suit newer divers, but the deeper wrecks (40–65 m) are technical dives. All Japanese ships and aircraft sunk here are protected state monuments and war graves; a Chuuk dive permit and a licensed guide are required, and taking anything is illegal.

Facts

• Best season: Dive year-round: the lagoon is sheltered and Thorfinn lists year-round diving
• Water temperature: About 28–30 °C
• Visibility: Typically 10–30 m (up to about 35 m on good days); silt and plankton reduce it inside wrecks and in the channels
• Currents: Little or no current on most wrecks – often like diving in a pool
• Getting there: Chuuk airport on Weno; the usual route is the United 'island hopper' from Honolulu or Guam. Liveaboards and dive shops collect guests at the airport
• Permit & protection: Chuuk State dive permit US$50, valid one year, sold by the licensed dive operators; guided diving only. Wrecks are state monuments and war graves – removing artefacts is illegal (fine up to US$1,000 / 6 months). Chuuk departure tax about US$30 (operators list it separately)
• Training level: Open Water is the minimum, Advanced/Deep and wreck training strongly recommended; wrecks deeper than 40 m (San Francisco Maru, Aikoku, Hokuyo, Nagano and others) are technical dives
• Hazards: Unexploded ordnance (shells, mines, bombs), fuel and caustic residues, sharp edges and silt inside wrecks – never touch cargo

Season

• Best months: Dec, Jan, Feb, Mar, Apr
• Acceptable: May, Jun, Jul, Aug, Sep, Oct, Nov
• Water temperature: 28–30 °C

Most sources recommend Dec–Apr (some Oct–May); Jun–Oct is wetter but the sheltered lagoon keeps diving going. Visibility often exceeds 30 m in the dry months.

Dive sites (40)

Aircraft wrecks

• A6M Zero Fighter (Eten) – 1–6 m, beginner
• A6M Zero Fighter (Fefan, upside down) – 11 m, beginner
• Betty Bomber (Mitsubishi G4M) – 15–21 m, beginner
• D4Y Judy Dive Bomber (Eten) – 6 m, beginner
• E13A Jake Seaplane – 20 m, beginner
• Emily Flying Boat (Kawanishi H8K) – 15 m, beginner

Fourth Fleet anchorage (east of Dublon)

• Aikoku Maru – 40–64 m, advanced
• Hoki Maru – 21–50 m, advanced
• Hokuyo Maru – 40–64 m, advanced
• Kikukawa Maru – 37 m, advanced
• Momokawa Maru – 27–43 m, advanced
• Nagano Maru – 40–67 m, advanced
• Nippo Maru – 24–47 m, advanced
• Ojima – 37 m, advanced
• San Francisco Maru – 45–64 m, advanced
• Seiko Maru – 20–50 m, advanced
• Shotan Maru – 37–58 m, advanced

Uman & southern lagoon

• Amagisan Maru – 30–58 m, advanced
• Gosei Maru – 3–30 m, intermediate
• Hino Maru No. 2 – intermediate
• Rio de Janeiro Maru – 9–34 m, intermediate
• Sankisan Maru – 3–30 m, intermediate
• Unkai Maru No. 6 – 18–40 m, advanced
• Yubae Maru – 15–37 m, intermediate

Dublon, Eten & Fefan channel

• Eissen 761 – 6–12 m, beginner
• Fujikawa Maru – 9–34 m, intermediate
• Futagami – 9–30 m, intermediate
• Heian Maru – 10–35 m, intermediate
• Hoyo Maru – 3–38 m, intermediate
• I-169 Shinohara Submarine – 27–43 m, advanced
• Kansho Maru – 12–40 m, advanced
• Kiyosumi Maru – 12–30 m, intermediate
• Sutsuki (Patrol Boat No. 34) – 7–14 m, beginner
• Yamagiri Maru – 15–34 m, intermediate

Western lagoon & Weno

• Fujisan Maru – 64 m, advanced
• Fumizuki – 21–43 m, advanced
• Hanakawa Maru – 3–34 m, advanced
• Shinkoku Maru – 10–38 m, intermediate
• USS Sgt. Major William J. Pugh – 7–15 m, beginner

North Pass & outer reef

• Oite – 55–61 m, advanced

Operators (4)

• SS Thorfinn (Seaward Holidays Micronesia) – liveaboard, Moored in Truk Lagoon off Dublon, Weno (Chuuk)
• Odyssey Adventures (MV Odyssey) – liveaboard, Weno, Chuuk (booking office: Ocala, Florida, USA)
• Master Liveaboards – Pacific Master (Truk Lagoon) – liveaboard, Weno, Chuuk
• Blue Lagoon Dive Shop (Blue Lagoon Resort) – dive centre, Blue Lagoon Resort, southwest tip of Weno Island, Chuuk

Routes (4)

• Truk Lagoon 7 nights (Odyssey)
• Truk Lagoon 7 nights (Master Liveaboards)
• Truk Lagoon 10 nights (Master Liveaboards)
• Thorfinn stay-and-dive plans (flexible length)

Site positions come from dive-operator maps and published guides and are for orientation only – never for navigation; where sources disagree this is marked. These wrecks are war graves and protected monuments: dive with a licensed guide, penetrate only with wreck training, and never touch ordnance or remove anything.