While fighters and high-level bombers kept the Japanese convoy occupied, the converted B 25s came at the Japanese so low that the blast of their propellers churned the sea. The Japanese skippers thought they were torpedo bombers—which they were, in a sense—and turned into the attack, to present the narrowest possible target, a wise maneuver ordinarily, but this also made the ships the best possible targets for the long, thin pattern of the machine-gun ripsaws mounted in the bombers’ noses. The ships were ripped from stem to gudgeon by the strafing runs. Then, when the pilots were sure the antiaircraft gun crews had been sawed to shreds, the low-flying B 25s charged at the ships broadside and released the skip bombs, which caved in hull plates at the waterlines and let in fatal doses of sea water. It was almost impossible to miss with a skip bomb. By nightfall the Bismarck Sea was dotted with rafts, lifeboats, and swimmers clinging to the debris of sunken ships. Only darkness stopped the slaughter from the air.
After that sunset, however, the slaughter from the sea became more grisly than ever. Eight PTs from New Guinea, under Lieut. Commander Barry K. Atkins, fought their way to the battle zone through the heavy seas in the wake of the storm which had so treacherously deserted the Japanese convoy.
Just before midnight they spotted the burning transport Oigawa Maru. PT 143 and PT 150 each fired a torpedo and blew the transport out of the water. The PT sailors searched all night but could find no other targets—largely because almost all of them were already on the floor of the Bismarck Sea.
When the sun came up they had targets enough, but of a most distasteful kind. The sea was swarming with Japanese survivors, and it was the unhappy duty of the PTs to try to kill them to the last man, so that they could not get ashore on nearby New Guinea.
On March 5th the same two PTs that had sunk the Oigawa Maru jumped a Japanese submarine picking up survivors from three boats. The PTs charged, firing torpedoes, but they missed the crash-diving submarine. Then they were presented with the hideous problem of what to do with the 100 helpless soldiers who watched fearfully from the three boats. The Japanese would not surrender, and they could not be allowed to escape.
The two PTs turned on the machine guns and set about the grim butchery of the unhappy Japanese. When the execution was over, they sank the three blood-drenched boats with a shallow pattern of depth charges.
Scout planes conned other PTs to lifeboats and rafts crammed with Japanese. More than 3,000 soldiers died, but so thick were the survivors that several hundred managed to swim ashore despite the best vigilance of the small-craft navy. The natives of New Guinea, who had long chafed against the Australian law forbidding head-hunting, were unleashed by the authorities and had a field day tracking down the few Japanese who made it to the beach.
Eighteen Japanese made an astonishing 400-mile voyage through PT-patrolled waters to a tiny island in the Trobriand group. They were captured by the crew of PT 114 in a pioneer landing party operation of the PT fleet.
The skip bombers of the American Air Force had sunk four destroyers and eight transports, killed 3,000 Japanese soldiers and sailors, and shot down 30 planes. The Battle of the Bismarck Sea was a smashing blow to the Japanese, and they never again risked a surface transport near eastern New Guinea (except for a one-night run of four destroyers in a feeble and abortive attempt to set up a spurline of the Tokyo Express.)
The American Navy had an official torpedo-boat doctrine, of course, and PT officers were well drilled in the proper manner of delivering torpedoes in combat before they left the States, but this night-prowling business against torpedo-proof barges called for new torpedo-boat tactics.