Dive Site: Honiara - Iron Bottom Sound

About Honiara - Iron Bottom Sound

Iron Bottom Sound, located between Guadalcanal, Tulagi, and the Florida Islands, is a legendary dive destination named for the vast amount of World War II wreckage that sank during the 1942-43 Guadalcanal Campaign. Hundreds of ships, aircraft, and submarines now rest on the seabed, transforming into vibrant artificial reefs. While many wrecks are in deep water beyond recreational limits, several are accessible to advanced divers, their hulls adorned with colorful corals and home to diverse marine species, including large groupers and reef sharks. Diving here offers a profound connection to history, with each wreck telling a story of specific battles and crews. Local guides enhance the experience by providing detailed historical context, turning every dive into an immersive living history lesson. The Solomon Islands are at the eastern tip of the Coral Triangle, boasting exceptional marine biodiversity due to powerful equatorial currents, which also feed the reefs of Iron Bottom Sound, creating a thriving ecosystem on these submerged relics. Accessibility ranges from shore dives for shallower wrecks to day boats and liveaboards for deeper sites. Honiara serves as the primary entry point, offering both land-based diving options for local wrecks and liveaboard departures to explore more remote sites within Iron Bottom Sound and beyond. The area seamlessly combines historical significance with rich marine biodiversity, making it a compelling destination for both history enthusiasts and passionate divers. This region is not a polished resort destination but an adventurous, history-rich, cash-based environment best navigated with local operators who understand customary land and reef ownership. The reward is unparalleled: deep WWII context both above and below the water, coupled with the warm, biodiverse waters of the Coral Triangle.

Dive site facts: Honiara - Iron Bottom Sound

Depth

5–70 m

Current

Mild to strong

Visibility

9–30 m

Water temperature

28–30 °C

Entry

Shore / Tender

Level

Advanced Open Water recommended, current and wreck experience helpful

Dive type

Wreck, historical, reef, macro

Night dive

Possible

Region / port

Guadalcanal Province

Coordinates

-9.4333, 160

Conditions & Currents

Currents in Iron Bottom Sound can vary from calm conditions, particularly in sheltered bay areas or near some shore-accessible wrecks, to light or strong currents around deeper wrecks and reef sites. Sites like the PBY Catalina Seaplane and Tama Maru may experience light currents, while the Azumasan Maru and Twin Tunnels Reef can encounter strong currents, necessitating careful dive planning and potentially requiring reef hooks. Visibility can range from 9 meters at muck sites to 30 meters at deeper wrecks, influenced by weather and local conditions. Divers should be prepared for varying conditions and consult local guides for the most accurate, real-time current assessments at specific wreck sites, as currents can change quickly and significantly impact the dive profile and safety stop locations.

Marine life & sighting chances

Nudibranch

occasional

Wrasse

common

Grey Reef Shark

occasional

Barracuda

common

Snapper

common

Bumphead Parrotfish

occasional

Grouper

common

Reef Shark

occasional

Batfish

occasional

Giant Clam

occasional

Chub

common

Damsel

common

Butterflyfish

common

Anthias

common

Dive profile & how the dive runs

Dive profiles in Iron Bottom Sound are highly site-specific due to the variety of wrecks and reef structures. For shore-entry wrecks like Bonegi I (Hirokawa Maru), you typically enter from the beach and navigate along the port side of the vessel. The bow starts in approximately 5 meters of water, descending gradually as you move along the deck structure, which is covered in corals and attracts schooling fish. Dives often involve exploring the exterior and accessible compartments, reaching depths of around 30 meters, before turning and ascending gradually back towards the shallows for a safety stop amidst the reef growth near the shoreline. For deeper wrecks accessed by boat, such as the USS Aaron Ward or Azumasan Maru, a descent line is typically used to reach the wreck. Divers will explore specific sections, maintaining awareness of depth and no-decompression limits, often following a guide along key features like gun turrets, cargo holds, or the stern. Ascent usually involves a slow, controlled rise along the descent line, with a mandatory safety stop conducted at 5 meters for 3 minutes, before surfacing to the boat. Current considerations are crucial for deeper dives, influencing entry and exit techniques.

Underwater photography

Iron Bottom Sound offers diverse photographic opportunities, from wide-angle wreck shots to macro critters on coral-encrusted relics. For large wreck subjects like the Hirokawa Maru or various aircraft, a wide-angle lens is essential to capture the scale and historical context. Natural light can be sufficient in shallower areas, but strobes are crucial for bringing out color and detail in deeper sections or inside compartments, especially with the intricate coral growth. For macro enthusiasts, a dedicated macro lens will highlight nudibranchs, pygmy seahorses, and small reef fish that inhabit the wrecks. Good buoyancy control is paramount to avoid disturbing delicate corals or stirring up sediment inside wrecks. Be respectful of the historical significance of the sites, avoiding contact with artifacts and maintaining a respectful distance to preserve these underwater museums.

Combine with nearby dive sites

• Bonegi I & II

  Shore-accessible WWII Japanese transport wrecks

• Twin Tunnels

  Volcanic reef with vertical lava tubes and diverse macro life

• Custom House Reef

  Custom House Reef in the Solomon Islands is a highly regarded dive site, notable for its exceptional biodiversity and healthy coral…

• P-39 Airacobra Wreck

  The P-39 Airacobra Wreck offers a unique connection to the Pacific War, providing a poignant and historically significant dive experience…

• Toa Maru

  Massive Japanese transport ship wreck, accessible from Western Province

Getting there & logistics

Honiara International Airport (HIR) on Guadalcanal is the main gateway to Iron Bottom Sound, with international connections from Brisbane, Nadi (Fiji), Port Moresby, and Auckland. Most liveaboards depart from Honiara, offering itineraries that typically combine Iron Bottom Sound with the Russell Islands, Florida Islands, and potentially Mary Island. Land-based diving is also available from Honiara, with local operators providing day trips to nearby wrecks like the Bonegi sites. Trip lengths vary, from a few days of land-based diving to week-long or longer liveaboard expeditions. While specific park fees are not always separate, it's customary to respect local land and reef ownership, often involving small payments to local communities for access. Liveaboards handle most logistics, but independent travel requires planning for cash transactions and basic facilities outside Honiara.

Safety & environment

Diving in Iron Bottom Sound, particularly on deep wrecks, requires adherence to advanced diving protocols. The nearest recompression chamber is located in Honiara, but medical facilities in the Solomon Islands are generally limited. In case of a serious diving accident requiring evacuation, the reality is that it will be complex and potentially lengthy. Therefore, comprehensive dive insurance that includes remote-evacuation coverage is not just recommended but absolutely essential. Site-specific hazards include potential strong currents, sharp edges on wrecks, and overhead environments. Always dive with a reputable operator and a knowledgeable guide, follow their briefings, maintain conservative dive profiles, and ensure your equipment is in excellent condition. Malaria is present on Guadalcanal, so consult your doctor about prophylaxis before travel.

Who it suits — and who it doesn't

FAQ

Honiara - Iron Bottom Sound FAQ

Liveaboards diving Honiara - Iron Bottom Sound

These liveaboards may visit Honiara - Iron Bottom Sound on selected itineraries — the exact dive sites depend on departure, weather and conditions.

Emperor Bilikiki

Solomon Islands

20 guests38 m

$569/day

Solomons Master

Solomon Islands

16 guests

$401/day

Pacific Master

Solomon Islands

20 guests30 m

$268/day