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IJN Submarines in the Solomons

By Andrew Whitehead

Published in Dive Log Australasia
November 2006


On a trip to Honiara in September 2006, we dived on the wrecked Japanese freighters at Bonegi Beach. When we returned our hire tanks to the local dive operator, I met an Australian man who had just driven 40 km up the coast to dive on the Imperial Japanese Navy Submarine I-1. This was of great interest to me because I have dived on this wreck only once before during a cruise on the MV Princess II.

On that trip, the Princess anchored off the tiny village of Tambea near Cape Esperance, while two crewmembers went ashore to pay the custom fee for diving on the wreck. The I-1 lies with the shattered bow in 5 metres and the stern in 30 metres. We geared up on the dive deck and made a plan to dive down to the stern of the submarine and then move slowly up the wreck to the shallow reef area.
We could see the long ‘cigar tube’ shape of the aft section of the submarine and swam down the outside to the stern. The propellers were salvaged in the 1960s so there is little to see at the stern. We swam along the circular deck and I entered the first area where the hull is fractured. There is a great deal of machinery inside and several large air cylinders. I swam through a small circular frame which must have once been a watertight door.
Back on the outside, the conning tower is nowhere to be seen. In addition, the sheer size of the operational submarine cannot be appreciated because the wreck is severely damaged. The forward half is blown wide open with debris all over the reef.  Apparently, the salvagers blew up the bow section which set off some live torpedoes in the torpedo room. We finished the dive on the shallow reef where we admired the colourful anemonefish.

The Solomon Islands are rich in history about the war in the Pacific and there are several wrecks at diveable depths. How the I-1 ended up on a reef near Cape Esperance, and the part it played in the Guadalcanal campaign makes an interesting story.

Supply Missions

American forces landed on Guadalcanal in August 1942 and took control of Henderson airfield. From then on, the Japanese found it very difficult to re-supply the surviving troops on Guadalcanal by ship and several vessels including the Hirokawa Maru, the Kinugawa Maru, the Kyushu Maru, and the Azumasan Maru were lost. By January 1943, the Japanese forces on Guadalcanal only had control of the northwest corner of the island, a fairly mountainous area around Cape Esperance, with the US forces moving along the north coast towards them.
In a desperate move, the Japanese navy used at least twelve of the older I-class submarines to bring food, ammunition and medical supplies from Rabaul and land them at night in Kamimbo Bay.
The supplies were usually carried in a 14 metre landing barge which was mounted on the rear deck. My research indicates that the following IJN submarines were used in supply missions: I-1, I-3, I-8, I-9, I-16, I-17, I-18, I-19, I-20, I-21, I-26, and I-31. About 13,000 Japanese army and navy personnel were evacuated by destroyers over three nights early in February 1943.
I-1 and I-3 were sunk near Cape Esperance during these missions
. I-3 was torpedoed about three miles off Cape Esperance where it is around 300 metres deep, and no one knows where it is. I-16 and I-18 were sunk nearby during later missions. In fact, eight submarines were lost between November 1942 and May 1944 in the Solomon Islands.

This brief history is used as some of the background material for my new adventure thriller entitled “SOLOMON QUEST”. In the novel, underwater adventurer Jim Lawrie is lured to the Solomon Islands by an offer to explore a newly discovered wreck. Jim meets his match with the feisty Rene Armstrong and life gets very dangerous for them as he struggles to uncover a secret that has rested on the sea floor since WWII.


According to Jane’s Fighting Ships of World War II, the I-1 was 320 feet (97.5 metres) long and had a displacement of 1955/2480 tons. I-1 was the first of the Junsen class of Japanese ocean-going submarines and was completed in 1926. It was originally armed with two 14cm deck guns, had six 21-inch torpedo tubes and a crew of 82. According to the I-1’s Tabular Record of Movement, the vessel was converted to a cargo-carrying role in August 1942 by removing the aft gun to make room for mountings to hold a 46-foot landing barge.

On 29 January 1943, the I-1 arrived off the coast with replacement troops, and a load of food supplies in rubber containers in the barge on the rear deck. The submarine was detected by the New Zealand corvettes HMNZS Kiwi and HMNZS Moa which dropped depth charges forcing it to surface, exchanged gunfire and rammed it three times. During the battle, the barge of supplies caught fire and the captain was hit by gunfire. The damaged submarine finally ran onto the reef off Tambea. Since the submarine carried codebooks, the Japanese armed forces tried to destroy it on several occasions, but failed to prevent the recovery of the books by the US Navy.


The I-3 was commissioned in November 1926 and was very similar to the I-1. On 9th December 1942, I-3 surfaced three miles off Kamimbo Bay. While the crew were preparing to launch the barge of supplies, two torpedo boats attacked with machine guns and torpedoes. The depth of the water at the reported position of sinking is variable but around 300 metres.


The I-15 was commissioned in November 1940. It was built as a long-range scout (Type B1) which carried a Yokosuka E14Y ‘Glen’ reconnaissance seaplane which was launched from a forward catapult. The submarine was 356.5 feet long, with a submerged displacement of 3,654 tons, a surface speed of 23.5 knots, a range of 14,000 nautical miles, and a crew of 94. Armament consisted of 6 forward torpedo tubes, and one 14cm deck gun aft.
Early in 1942, the Japanese Navy General Staff developed a plan to raid Pearl Harbour again using flying boats
with the objective of disrupting ship repair activities. The plan involved five I-class submarines and two Kawanishi H8K1 ‘Emily’ flying boats. In preparation for the mission, the seaplanes were removed from the I-15 and two other submarines and the hangars modified to accommodate fuel tanks. In March 1942 the two ‘Emily’s’ flew from Wotje in the Marshall Islands to a remote shoal in the Hawaiian Islands where they were refuelled by the I-15 and the I-19. The flying boats departed and bombed Honolulu through heavy cloud cover at night causing little damage.
On 10 November 1942, I-15 was sighted on the surface west of San Cristobal by the minesweeper USS Southard. After hours of depth charging, the I-15 was forced to the surface and sunk with all hands in the deep passage between Guadalcanal and San Cristobal.


The I-16 was commissioned in March 1940. It was built as a Type C1 which was designed to carry a midget submarine on the aft deck. The submarine was 358.5 feet long, with a submerged displacement of 3,561 tons, a surface speed of 23.5 knots, a range of 14,000 nautical miles, and a crew of 101. Armament consisted of 8 forward torpedo tubes, and one 14cm deck gun forward.
In December 1941, the I-16 participated in the attack on Pearl Harbour as one of five mother ships that launched midget submarines. It is not known whether the midget caused any damage and it failed to return to the I-16.
The I-16 was more successful at commerce raiding where it sank four merchant ships in the Indian Ocean during June and July 1942.
The I-16 participated in three separate midget submarine attacks on shipping near Lungga Point (east of present-day Honiara) from a base in the Shortland Islands during November and December 1942. In the first attack, the rudder of the midget HA-30 was damaged during the launch. The midget lost steering, was then scuttled and the crew escaped to Cape Esperance. In the second attack, the HA-10 torpedoed and damaged a freighter but the crew were lost. In the third attack, the HA-22
fired both torpedoes at a destroyer but missed. The crew scuttled the midget and escaped to Cape Esperance.

In May 1944 on a supply mission from Truk Lagoon to Bougainville, the Allies intercepted a signal from the 1-16. The submarine was sighted on the surface by an aircraft about 220 km northeast of Cape Alexandra, Choiseul on 19 May 1944. The I-16 was then sunk by depth charges from the USS England.
The depth of the water at the reported position of sinking is over 1000 metres.


The I-18 was commissioned in January 1941. It was also built as a Type C1 submarine. In December 1941, the I-18 participated in the attack on Pearl Harbour. The midget was depth charged and sunk in the Keehi Lagoon just off Pearl Harbour. The I-18's midget was raised in 1960 and returned to Japan where it is now on display at the Naval Tactical School No. 1 at Eta Jima, Hiroshima.
On 11 February 1943, I-18 sent a sighting report and was then sunk by depth charges from the destroyer USS Fletcher in the Coral Sea, 200 miles south of San Cristobal.


The I-22 was commissioned in March 1941 as a Type C1 submarine. The I-22 participated in the attack on Pearl Harbour where its midget was sighted after entering the harbour rammed, sunk and depth charged. It was later raised and used as landfill.
In May 1942, the I-22 participated in the midget submarine attack on Sydney Harbour by launching HA-21. The midget was sighted after entering the harbour and disabled by depth charges.
HA-21 was later salvaged along with I-27's midget HA-14. Parts of the two submarines were joined together to form a single midget that is on display at the Australian War Memorial in Canberra.
On 1 October 1942,
the I-22 sent a sighting report of a convoy 40 miles southeast of Malaita then all contact with the submarine was lost, position unknown.


The I-123 was commissioned in April 1928. It was built as a Type KRS which was based on a WWI German U-boat design specifically for laying mines. The submarine was 279.5 feet long, with a submerged displacement of 1,768 tons, a surface speed of 14.5 knots, a range of 10,500 nautical miles, and a crew of 75. Armament consisted of 4 forward torpedo tubes, and one 14cm deck gun forward.
I-123 spent some of its war patrols laying mines in the Philippines, Java, near Darwin, and in Torres Strait. I-123 was sunk on 29 August 1942 by depth charges from the old minesweeper USS Gamble in Indispensable Strait northeast of Guadalcanal at a depth of about 1000 metres.


The I-72 (later renumbered as I-172) was commissioned in April 1937 as a Type KD6 attack submarine. It was 343.5 feet long, with a submerged displacement of 2,440 tons, a surface speed of 23 knots, a range of 14,000 nautical miles, and a crew of 70. Armament consisted of four forward torpedo tubes, two aft tubes, and one 10cm deck gun forward.
The I-172 was modified to carry a landing craft, amphibious tank or other external equipment at Truk Lagoon in October 1942. I-172 then left Truk on her third patrol to support a midget submarine attack on shipping off Lungga Point, Guadalcanal. On 3 November 1942, eight days after the Battle of Santa Cruz, the I-172 sent a sighting report in the Solomon Sea southeast of Guadalcanal, then all contact with the submarine was lost, position unknown.

A full account of the fate of these submarines can be found in the Imperial Japanese Navy website

Jane’s Fighting Ships of World War II
Submarines of World War II
, John Ward, 2001.
SUBMARINES, War Beneath the Waves
, Robert Hutchison, 2001.

Visiting the Solomons

Scuba diving is available from Honiara, Tulagi, Munda, Uepi or Gizo, and also on liveaboard cruise vessels based in Honiara. As from 10 November 2006, Solomon Airlines will have scheduled flights between Brisbane and Honiara each day using Boeing 737 aircraft. Visitors from Commonwealth countries and the United States do not require visas. Henderson Airport is situated approximately 10 minutes drive from the capital of Honiara.

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