Battle of the Bismark Sea (World War 2, 2 March 1943 to 4 March 1943)

About This Campaign


Battle of the Bismark Sea, South West Pacific 2-4 March 1943

Land based aerial attack of ships had led to the catastrophic demise of British Naval Power in SE Asia, when in February 1942, the Prince of Wales and Repulse were sunk off Malaya.

Naval airpower was the dominant actor in most naval engagements in the South West Pacific, such as Coral Sea and Midway in 1942.  There was one spectacular exception.


The Battle of the Bismark Sea heralded the start of the fight for northern New Guinea, following Japanese defeats at 'the Beachhead Battles at Buna Gona and Sanananda,  on Papua's north coast, and Guadalcanal in the Solomons.  

Forced  out of the Buna, Gona and Sanandana area,  and in all likelihood,  unable to hold Guadalcanal, the Japanese switched their priority from the Solomons to the north coast of New Guinea.

The strategically located and heavily defended main Japanese base at Rabaul had oversight of each of the theatres of conflict as well as air and maritime operations.  Rabaul had excellent facilities for all three.  It was also key to the sustainment of Japanese forces in the South West Pacific.

Fig1. Map illustrating the relative locations of key bases, convoy routes air strike routes and results over the course of the battle.s Public Domain,

The Japanese Command had no intention of relinquishing further territory in New Guinea, particularly in the Lae area, which they had occupied since March 1942.  It was also home to an important air base within easy range of Port Moresby.

Fig 2.  Simpson Harbour, Rabaul, Japan's key base in the South West Pacific Area, crowded with shipping

Japanese Preliminary Operations

During December and January 1942, a Plan was hatched to land additional troops at Madang and Wewak, and to reinforce the Lae garrison, by sea.  Their initial intent was to capture Wau, a strategic inland town in the New Guinea Highlands, lightly held by a small Australian detachment called ‘Kanga Force’, largely comprised of the 2nd/5th Independent Company.

The Japanese despatched a convoy from Rabaul on 5 January, transporting General Okabe’s 5th Division.  US Intelligence were forewarned of the Convoy through ‘Ultra’, the secret Allied codebreakers transcripts.

A medium level bombing raid by B-17s, produced disappointing results.  USAAF and RAAF patrol aircraft detected, shadowed and attacked the convoy en-route, despite it being masked by cloud and protected by a fighter escort.  An RAAF Catalina sank one of the transport ships, with most of those on board being rescued by escorting vessels.

Fig 3. An RAAF Catalina Maritime Patrol flying boat.

Despite this, the force was landed on 7 January and advanced on Wau, where it was subsequently thwarted by Kanga Force which unbeknown by the Japanese had been reinforced by and placed under command of the 17th Infantry Brigade, flown up from Milne Bay via Port Moresby, in anticipation of the Japanese move on Wau.

More Japanese forces, comprising the bulk of the 10th Division, landed at Wewak on 19 January.

At that point it was planned that the Command Group of XVIII Army and the main body of the 51st Division would move from Rabaul to Lae on 28 February.  The scene was set.


Experience to date was that level bombing from medium and high altitude was largely ineffective against moving ships.

The alternative was very low level attack, but it was high-risk.  Techniques were practiced and ‘skip bombing’ appeared to offer the greatest chance of success.  Aircraft practiced on a beached wreck in Port Moresby Harbour.  The aircraft released their bombs short of the target such that they bounced off the surface of the water and into the side of the target.  This required delayed action fusing on their bombs.

The line of approach meant that the aircraft would be in range of even light shipboard anti-aircraft defences,  so it was decided they needed forward firing armament to suppress enemy defensive fire.

Fig 4. A No. 22 Squadron A-20. Ground-crew servicing an A-20 fitted with a straffing pack of .50 cal HMG in the nose.  Others could be added in sponsons on either side of the forward fuselage.  AWM unreferenced image

Three aircraft types, all twin engined, appeared particularly suited to this role.  North American B-25 medium bombers were fitted with up to ten forward firing Browning M2 .50 cal heavy machine guns in the nose of the aircraft.  A-20 ‘Havoc’ (or 'Boston in RAAF service) light bombers, including those operated by No. 22 Squadron RAAF among other US units, were similarly equipped.  The newly arrived No. 30 Squadron RAAF was flying the fast and very heavily armed Bristol Beaufighter, new to the theatre and equipped with four 20mm cannon in the nose and another six .303 machine guns in the wings, a perfect strafer.

The next challenge was to be able to concentrate sufficient aircraft so that a worthwhile strike force could be assembled.

US aircraft would be operating from Port Moresby, while the RAAF flew from Buna and Milne Bay as well.  The latter was renowned for bad weather and US units refused to fly from there, because the perforated steel plate sunways were perpetually wet and slippery.

Now all that was required was good intelligence, weather to suit and a measure of luck.

2 March

The Japanese convoy of eight destroyers and eight troop transport departed Simpson Harbour on 28 February, escorted by over 100 fighter aircraft, titled  ‘Operation 81’ by the Japanese Command.  There were nearly 7,000 troops on board as well as aviation and other fuels, ammunition and combat stores and rations.

Playing in favour of the Allies was the glacial speed of the convoy, dictated by the slowest ships in the group; a mere 7 knots.

Two storms fortuitously masked the convoy from Allied patrols, but late on 1 March a US B-24 Liberator spotted the convoy.  Eight B-17s were despatched but failed to find the convoy.

At dawn on 2 March, No. 22 Squadron RAAF sent six A-20 Havocs (originally Dutch aircraft destined for the Netherlands East Indies) to suppress air operations at Lae.

Fig 5.  A Japanese ship desperately tries to manouevre admidst a bracket of bombs during the Battle of the Bismark Sea.  AWMI8159

Another B-24 spotted the convoy, and two waves of B—17s were despatched totalling 28 aircraft.  Supposed to rendezvous with P38 Lightning escorts, the B17s arrived early and were attacked by the convoy's fighter escort until the P38s arrived.  The net outcome was that one transport was sunk and eight Japanese fighters were lost against three US P38s and nine B17s sustained battle damage.  Escorting destroyers which had picked up survivors, broke away from the convoy to deliver the troops to Lae. 

3 March

A force of eight RAAF Beaufort torpedo bombers from No. 100 Squadron was launched, but they flew into bad weather off the southern tip of New Britain and only two found the convoy, and were unable to achieve any hits.  They did serve to alert the Japanese to the potential of further torpedo attacks, which would have dire consequences as it dictated the tactics they would adopt.

Concurrently, No.22 Squadron RAAF had sent just about every A-20 it had, 22 in all, against Lae, to suppress any enemy attempts to interdict the air fleet approaching the Huon Gulf. 

A total of 90 aircraft had been despatched comprising B-17s, B-25s, A-20s and RAAF Beaufighters.  They rendezvoused off Cape Ward hunt, a readily identifiable way point used by both sides to aid navigation particularly in bad weather.  But 3 March was bright and clear; an ominous portent for the Japanese.

At about 10:00am, the main attack began.  B-17s and B-25s began level bombing attacks which caused the convoy to scatter. Meanwhile Zeros and US P-38 Lightning escorts tangled in wild dog-fights.

Next on the scene were the Beaufighters, approaching at mast-head height.  Fearing a torpedo attack, the Japanese ships turned to face them, to minimise their profile to torpedoes.  Instead, the Japanese ships presented the perfect strafing target, offering the length of the ship to the 20mm cannon and machine guns of the Beaufighters.  The results were devastating with many ships officers becoming casualties as the ship’s bridges wore the fury of concentrated raking 20mm cannon fire.

B-25s followed skip bombing the lumbering transports  and achieved some spectacular hits on escorting destroyers.

Garrett Middlebrook was a co-pilot in one of the B-25s, and described the ferocity of the strafing attacks:

“They went in and hit this troop ship. What I saw looked like little sticks, maybe a foot long or something like that, or splinters flying up off the deck of ship; they’d fly all around... and twist crazily in the air and fall out in the water. Then I realized what I was watching were human beings. I was watching hundreds of those Japanese just blown off the deck by those machine guns. They just splintered around the air like sticks in a whirlwind and they’d fall in the water”.[1]

The Admiral’s flagship the destroyer Shirayuki was first hit, initially by a staffing Beaufighter and then a bombing attack.  Admiral Kimura was wounded and among the many casualties on the bridge.  A bomb hit sheared off the stern and it began to sink.  Another destroyer collided with a transport and both were abandoned.

Fig 6. A 5th Air Force B-25 strafer completes a bomb run on a Japanese destroyer 

In the afternoon B-25s and A-20s returned including No. 22 Squadron RAAF and their A-20s.  The carnage continued as more B-17s returned.  By now, seven of the eight transports were on fire or sinking, along with three of the eight destroyers.  The remainder were busy gathering up survivors and four of them headed for Rabaul with over 2,000 survivors on board. Only one was undamaged.

Then the last of the eight Japanese destroyers still in the area, the Asashio , was hit and sunk by a B-17, while picking up survivors of earlier sinkings.


From any angle, it was a disaster for the Japanese.

All eight transport ships were sunk, along with four destroyers.

Fig 7. Filmed from the cockpit of a RAAF Beaufighter, by celebrated war photogpaher Damien Parer during the Battle of the Bismarck Sea.  A Japanese troop transport ablaze and sinking as another Beaufighter attacks.  A still taken from a movie Parer made whilst sitting behind the pilot.

Out of 6,900 troops who were badly needed in New Guinea, only about 1,200 made it to Lae, and about 2,700 were recovered to Rabaul.

The Allies lost 13 aircrew, 10 of whom were lost in combat while three others died in an accident. There were also eight wounded. Aircraft losses were one B-17 and three P-38s in combat, and one B-25 and one Beaufighter in accidents.

MacArthur issued a communiqué on 7 March stating that 22 ships, including twelve transports, three cruisers and seven destroyers, had been sunk along with 12,792 troops - as always playing for kudos via the media.

Army Air Force Headquarters in Washington, D.C. looked into the matter in mid-1943 and concluded that there were only 16 ships involved, but GHQ SWPA considered the original account accurate.

However, the most important result was the beginning of the end of the Japanese merchant fleet that sustained their newly-won empire, eventually crippling their capacity to supply their troops and keep them in the fight.  Allied Intelligence, airpower and once they got their notorious Mk14 torpedo sorted out, the US Navy's submarine fleet would do the rest.  Low level bombing and ‘strafers’ were to become a standard in the SWPA, and now 80 years later, it is apparent that these momentous events of late 1942-43 signalled the setting of the Empire of the Rising Sun that had been carved out just one year prior.

As a footnote, having made such a spectacular debut in the SWPA, the Bristol Beaufighter went on to become a stalwart of the RAAF aircraft inventory.

Fig 8.  A very early photograph of a Beaufighter in Australian service with the the yellow outer ring of the roundel and the red inner dot still appled.  In the background, a P-39 Airacobra.  Fast rugged reliable and heavily armed it was a highly regarded aircraft by all who flew in it. 'Two engines followed by an airframe' was a tag often applied.  Its two mighty Hercule sleeve-valved radial engines gave it a  distinctive sound.

The Beaufighter went on the be manufactured in Australia as the most heavily armed version of the aircraft built.  The Mk21 version produced by the Government Aircraft Factory in Melbourne, saw the six .303 MG replaced by four .50 cal, the addition of a distinctive autopilot 'blister' on the nose and, like its European theatre counterparts, it was armed with eight x three inch unguided rockets.  It was one of the few aircraft operated by the RAAF in both major theatres of operation (SWPA and NW Europe), with great distinction.  It served in every theatre of war that the RAF  / RAAF were engaged in, and in many roles, including as a nightfighter.  It performed a remarkably similar role in the North Atlantic, interdicting German merchant shipping, which was much more heavily defensively armed than that of the Japanese.  


Compiled by Steve Larkins March 2023 - long overdue


1. Odgers, George (1957). Air War Against Japan 1943–1945. Australia in the War of 1939–1945: Series 3 – Air. Vol. 2. Canberra: Australian War Memorial. OCLC 1990609.

2. McAulay, Lex (2008). Battle of the Bismarck Sea: 3 March 1943. Maryborough, Queensland: Banner Books. ISBN 978-1-875593-32-3. OCLC 271780681.

3. Bergerud, Eric M. (2000). Fire in the Sky: The Air War in the South Pacific. Boulder, Colorado: Westview Press. ISBN 0-8133-3869-7. OCLC 42002639.

I have recently obtained a copy of Michael Veitche's title of the same name, but too late to be referenced in this article.


[1] Begurud pp 592



Showing 1 person of interest from campaign

HASTWELL, Leonard Raymond

Service number 407579
Flight Lieutenant
RAAF Headquarters (Melbourne / Brisbane)
Royal Australian Air Force
Born 16 Jan 1918