Iron Bottom Sound · Solomon Islands · Wreck
Bonegi I
A 155 m Japanese transport you reach by walking off the beach
Area photo: Jenny Scott from Adelaide, Australia · CC BY 2.0
Bonegi I is the wreck of the Japanese Army transport Hirokawa Maru, beached on Guadalcanal in November 1942 and dived straight off the sand west of Honiara. The bow sits in shallow water a short swim from the beach and the hull runs downhill on its port side to a stern at 55 m, so divers choose their depth simply by how far out along it they go.
Also known as Hirokawa Maru, Bonegi 1.
Where it is and how deep
9.3844° S, 159.8741° EApproximate position — the dashed circle shows where the site lies; your operator's briefing has the mooring.
The dive
You kit up on the sand and walk in: there is no boat and no mooring, just a short swim out over the shallows until the bow appears. The shallowest structure sits close to the beach in shallow water, crusted in the coral growth that has covered the hull since 1942, and it serves as both the start and the end of the dive. From there the wreck leads away downhill, so the only real decision is how far along it you intend to go before turning.
Following the hull out, the midships section lies over on its port side and the plating is broken by torpedo holes you can work through, with cargo still visible in the holds — Bonegi I is the more loaded of the two Bonegi wrecks. Fish move through the frames, turtles and blue-spotted stingrays pass over the sand alongside. Navigation is simple: out along the wreck until your turn depth, then back along the wreck.
Depth builds steadily the further aft you go, and the stern lies at 55 m — past recreational limits and well past what a shore dive should tempt anyone into — so most divers turn on the mid-hull and spend the rest of the dive shallow. Coming back up the slope leaves plenty of gas for a long finish around the bow, where garden eels stand in fields off the wreckage and cuttlefish and octopus sit in among the plating. The exit is the beach you started from.
The wreck
- Vessel
- Hirokawa Maru
- Type
- Japanese Army transport
- Length
- 155 m (509 ft)
- Built
- 1940
- Sunk
- 1942
- Cause
- Beached to land troops, then attacked and set ablaze
- Lies
- Bow in shallow water near the beach, midships on its port side, stern at 55 m
Hirokawa Maru was laid down at Kawasaki in April 1939, launched in May 1940 and completed that October. She was part of a Japanese reinforcement convoy broken up by American air attacks on 14 November 1942, and the following day she was run onto the Guadalcanal shore to land her troops. The grounded vessel came under renewed attack and was set ablaze. What was left has stayed on the beach slope ever since, now covered in corals and supporting a variety of marine life.
Marine life and season
- Sea turtles
- Stingrays
- Octopus & cuttlefish
- Macro critters
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Fair | Fair | Good | Prime | Prime | Prime | Good | Good | Good | Prime | Prime | Good |
Season follows Iron Bottom Sound: Apr–Jun and Oct–Dec are calmest; the Jan–Mar wet season brings runoff that cuts visibility on the shore wrecks.
Know before you go
- The hull runs continuously downhill to a 55 m stern with no natural stopping point, so agree a turn depth on the beach and watch your gauge rather than the wreck.
- The midships section lies on its port side with cargo still in the holds; going inside is an overhead dive that needs wreck training and lights, not a look on the way past.
Dive videos
WW11 Wreck dive Hirokawa Maru ‘BONEGI 1’Guadalcanal Solomon Islands · calvin entermann on YouTube
Freediving Solomon Islands | Hirokawa Maru | Bonegi I Wreck | GoPro · Omni Reef on YouTube
Questions divers ask
How deep is the Bonegi I wreck?+
The bow lies in shallow water close to the beach and the hull runs downhill to a stern at 55 m. Most recreational divers turn well before the stern and spend the dive on the midships and bow sections.
Can you dive Bonegi I from the shore?+
Yes. Bonegi I is a shore dive west of Honiara: you assemble kit on the sand at Bonegi Beach and walk in, with no boat involved.
What ship is Bonegi I?+
The Japanese Army transport Hirokawa Maru, 155 m long, completed in October 1940 and beached on Guadalcanal on 15 November 1942 during a reinforcement operation.
Sources
- Japanese transport Hirokawa Maru — Wikipedia
- Diving Sites in Solomon Islands — Dive The World
- Bonegi Beach, Guadalcanal — OpenStreetMap
In The Logbook
- DPV diving: what an underwater scooter changesGear & kit · 10 min read
- WWII wrecks you can dive, by theatreWrecks · 7 min read
- The best shore dives in the worldShore diving · 8 min read
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