Dive Site: San Francisco Maru

About San Francisco Maru

The San Francisco Maru, often dubbed the "Million Dollar Wreck," is among the most celebrated dive sites in Micronesia's Chuuk Lagoon, a renowned graveyard of World War II vessels. Sunk during Operation Hailstone in February 1944, this former Yamashita Kisen K. K. freighter, converted for military transport, lies upright on the seabed, brimming with a fascinating array of cargo. While the wreck’s shallowest point, its masts, reach 32 meters, its main deck starts around 50 meters, extending to the sand at approximately 62 meters. The vessel is laden with military hardware, including tanks, trucks, mines, bombs, and ammunition, providing an unparalleled underwater museum experience. Its depth positions it as a challenging yet highly rewarding dive. Despite its wartime origins, the San Francisco Maru has been transformed into a thriving artificial reef. Hard and soft corals, sponges, and sea fans now encrust its metal structure, attracting diverse marine life. Barracuda and jacks patrol the upper sections, while smaller reef fish, nudibranchs, and crustaceans inhabit its various nooks and crannies, showcasing the resilience of nature. Due to its significant depth, this dive is primarily suited for advanced recreational divers comfortable with short bottom times and decompression obligations, or for technical divers seeking extensive exploration. Liveaboards provide the most practical access to this and other deep wrecks within the lagoon, ensuring divers can maximize their experience with appropriate planning and support.

Dive site facts: San Francisco Maru

Depth

32–62 m

Typical dive

50–56 m, 5–10 min bottom time for recreational divers

Current

Mild

Visibility

15–40 m

Water temperature

28–30°C

Entry

Liveaboard tender / mooring line

Level

Advanced Recreational / Technical

Dive type

Wreck, Deep

Region / port

Chuuk Lagoon, Micronesia

Coordinates

7.358, 151.85

Conditions & Currents

Currents within Chuuk Lagoon are generally mild, especially in the sheltered areas where many wrecks, including the San Francisco Maru, are located. However, divers should still be prepared for light currents, particularly when ascending or descending. Visibility can fluctuate between 15 to 40 meters, with the best conditions typically found during the dry season. The depth of the San Francisco Maru, with its deck at 50 meters and the seabed at 62 meters, necessitates careful dive planning and strict adherence to bottom times and decompression procedures. Divers should monitor their air consumption closely and be comfortable with extended safety stops, as local dive guides prioritize their own deco limits after repeated deep dives.

Marine life & sighting chances

Barracuda

common

Jacks

common

Reef sharks

occasional

Groupers

common

Turtles

occasional

Nudibranchs

common

Crustaceans

common

Hard corals

common

Soft corals

common

Sponges

common

Sea fans

common

Dive profile & how the dive runs

Diving the San Francisco Maru typically begins with a descent down a mooring line to the bridge, which sits around 45-50 meters. Recreational divers often aim for the main deck at 50-56 meters to view the three Type 95 Ha-Go tanks. One tank appears to be mounting another on the starboard side, with a third on the port side. After examining the tanks, the dive usually continues to Hold No. 2, which contains intact trucks, some designed to carry water or fuel. Hold No. 1, further forward, houses landmines and aerial bombs. Due to the depth, bottom times are brief, often 5-10 minutes for recreational divers, making a quick tour of these key features essential. The ascent is long and slow, incorporating multiple decompression stops to manage nitrogen loading. Safety stops are conducted in the shallower water, where divers can enjoy the marine growth on the upper structures of the wreck and reef above.

Underwater photography

Photographing the San Francisco Maru demands careful planning due to its depth and the low light conditions. Wide-angle lenses are essential to capture the sheer scale of the wreck, particularly the tanks on the deck and the extensive cargo in the holds. External strobes are highly recommended to bring out the vibrant colors of the corals and marine life that now adorn the ship, as well as to illuminate the deeper, darker sections. Practicing excellent buoyancy control is crucial to avoid stirring up the fine silt inside the holds and maintaining clear shots. Given the short bottom times, prioritize key subjects like the tanks and unique artifacts. Tech divers with longer bottom times can explore the details of the bridge and deeper cargo holds more extensively.

Combine with nearby dive sites

• Fujikawa Maru

  Another popular wreck with aircraft and machine guns in holds

• Shinkoku Maru

  A tanker wreck known for its engine room and abundant marine life

• Heian Maru

  A large submarine tender with torpedoes and periscopes

• Nippo Maru

  Features tanks, artillery pieces, and gas masks

• Yamagiri Maru

  Known for its large artillery shells in the cargo holds

Getting there & logistics

Access to Chuuk Lagoon is primarily via flights to Weno Island (TKK), typically involving connections through Guam (GUM) and Honolulu (HNL) on United Airlines. From Weno, liveaboards or day boats transfer divers to the various dive sites. Liveaboards are the preferred method for diving the San Francisco Maru and other deep wrecks, offering multiple dives per day and efficient access to remote sites. Trips typically range from 7 to 10 days, providing ample opportunity to explore numerous historical wrecks. While there are no specific park fees mentioned, dive operators will handle any necessary permits. Booking several months in advance is highly recommended due to the popularity and limited availability of liveaboard spaces.

Safety & environment

Diving the San Francisco Maru requires strict adherence to deep diving protocols due to its depth (up to 62 meters). Divers must possess advanced or technical certifications and be comfortable with potential decompression obligations. Always dive with a reputable operator and an experienced guide, particularly on this wreck. The nearest recompression chamber is located at the Chuuk State Hospital in Weno, though evacuation procedures for serious incidents can be complex and time-consuming. Comprehensive dive insurance, covering medical emergencies and evacuation, is absolutely essential. Divers should meticulously plan their gas consumption, bottom times, and decompression stops. It is crucial to respect the wreck by avoiding penetration without proper training and equipment, and refraining from removing any artifacts.

Who it suits — and who it doesn't

FAQ

San Francisco Maru FAQ

Liveaboards diving San Francisco Maru

These liveaboards may visit San Francisco 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

$360/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