Dive Site: Nippo Maru

About Nippo Maru

The Nippo Maru offers a unique and eerie dive experience within the world-renowned Truk Lagoon, a significant historical site from World War II. This Japanese army cargo ship, resting upright on the seabed, forms a central part of the underwater memorial created by Operation Hailstone in 1944. It is widely regarded as one of the most compelling wreck dives globally, blending military history with thriving marine ecosystems. Sitting at depths accessible to advanced recreational divers, the Nippo Maru's structure provides numerous points of interest. Its holds still house a remarkable collection of war artifacts, including light tanks, artillery pieces, trucks, and gas masks, preserved almost exactly as they were when the ship sank. The wreck's kingpost, particularly, is a major highlight, serving as both a navigational aid and a bustling micro-habitat. Over the decades, the Nippo Maru has transformed from a sunken vessel into a vibrant artificial reef. Its metal surfaces are now covered in soft corals, sponges, and sea fans, attracting a diverse range of marine life from schooling fish to various macro creatures. Visibility here is generally excellent, especially during the dry season, allowing for clear views of both the historical cargo and the colorful biological growth. Diving the Nippo Maru is an immersive journey through history, offering both a somber reflection on conflict and a celebration of marine resilience.

Dive site facts: Nippo Maru

Depth

42 m (max)

Typical dive

12–42 m, 50–60 min

Current

Mild

Visibility

15–40 m

Water temperature

27–30°C

Entry

Liveaboard tender / negative entry

Level

Advanced Open Water, Wreck Diver

Dive type

Wreck, historical, deep, technical

Night dive

Possible at select sites in the lagoon

Region / port

Chuuk Lagoon, Federated States of Micronesia

Coordinates

7.365, 151.832

Conditions & Currents

Currents within Truk Lagoon, and specifically around the Nippo Maru, are generally mild, making for a more comfortable wreck diving experience. While the lagoon's sheltered nature protects most sites from strong oceanic flows, occasional moderate currents can be present, especially near passages. Divers should anticipate water temperatures ranging between 27-30°C year-round. Visibility is typically good, often exceeding 30 meters, though it can vary with rainfall. Entry and exit are usually boat-based, often via tender from a liveaboard, allowing for precise positioning over the wreck. Buoyancy control is crucial to avoid disturbing historical artifacts and sediment.

Marine life & sighting chances

Grey Reef Shark

occasional

Hawksbill Turtle

occasional

Barracuda

common

Trevally

common

Coral Grouper

common

Napoleon Wrasse

occasional

Bumphead Parrotfish

occasional

Triggerfish

common

Whitetip Reef Shark

occasional

Nudibranch

common

Shrimp

common

Crab

common

Juvenile Angelfish

common

Eels

common

Dive profile & how the dive runs

Your dive on the Nippo Maru typically begins with a descent along the mooring line directly to the wreck's superstructure. The ship sits upright, allowing for easy orientation. Divers often explore the deck first, noting the guns and the prominent kingpost, which is teeming with macro life. From there, you can descend into the holds to observe the tanks, trucks, and artillery pieces. The gas masks found in one of the cargo holds offer a particularly poignant sight. The dive typically progresses through various deck levels and accessible internal areas, maintaining an awareness of depth and no-decompression limits. The return ascent allows for further exploration of the coral-encrusted upper sections before commencing a safety stop, often enjoyed near the vibrant kingpost, which provides ample photographic opportunities in the shallow sunlit waters.

Underwater photography

The Nippo Maru offers fantastic opportunities for both wide-angle and macro photography. For capturing the immense scale of the wreck, including its military cargo and the surrounding reef growth, a wide-angle lens is essential. Consider using external strobes to illuminate the darker sections of the holds and bring out the vibrant colors of soft corals on the exterior. When focusing on macro subjects, such as nudibranchs and small reef fish found on the kingpost and deck, a macro lens with a focus light will yield excellent results. Maintain impeccable buoyancy to avoid stirring up sediment within the holds, which can quickly reduce visibility for both you and subsequent divers, and always respect the historical integrity of the artifacts; do not touch or move them for a shot.

Combine with nearby dive sites

• Fujikawa Maru

  Famous for its Zero fighter planes and soft coral coverage.

• Shinkoku Maru

  Tanker with intact medical supplies and prolific coral growth.

• Yamagiri Maru

  Wreck holding large artillery shells and a steamroller.

• San Francisco Maru

  Known as the 'Million Dollar Wreck' with tanks, trucks, and bombs.

• Heian Maru

  Large submarine tender with periscopes and torpedoes.

Getting there & logistics

Access to Chuuk Lagoon is primarily via Chuuk International Airport (TKK), with flights typically connecting through Guam or other Micronesian hubs. Upon arrival, dive operators, particularly liveaboards like the M/V Odyssey, arrange transfers to their vessels. Liveaboards are the preferred method for diving the Nippo Maru and other Truk Lagoon wrecks, offering unparalleled access and convenience. Trip lengths vary, but itineraries often span 6-10 days to allow for multiple dives on various sites, including the deeper wrecks. Marine park fees may apply and are often included in liveaboard packages. Combining Truk with other Micronesian destinations like Palau is common for extended dive holidays, though logistics between islands require careful planning.

Safety & environment

Diving the Nippo Maru requires advanced dive training, including wreck diving and potentially deep diving certifications, given its depth of up to 42 meters. The nearest recompression chamber is located within Chuuk Lagoon, offering critical medical support. Divers should ensure they have comprehensive dive insurance that covers emergency medical evacuation and hyperbaric treatment. Prudent conduct includes strict adherence to dive plans, conservative gas management, and maintaining excellent buoyancy control, especially when penetrating the wreck, to avoid disturbing sediment or damaging artifacts. Always dive with a reputable operator and a knowledgeable guide, as some areas of the wreck may have sharp edges or overhead environments.

Who it suits — and who it doesn't

FAQ

Nippo Maru FAQ

Liveaboards diving Nippo Maru

These liveaboards may visit Nippo Maru on selected itineraries — the exact dive sites depend on departure, weather and conditions.

Palau Siren

Micronesia

16 guests

$501/day

Solitude Gaia

Micronesia

18 guests40 m

$310/day

Palau Aggressor II

Micronesia

18 guests32 m

$292/day

Black Pearl

Micronesia

24 guests

$390/day

Ocean Hunter 3

Micronesia

16 guests29 m

$350/day

Pacific Master

Solomon Islands

20 guests30 m

$268/day