Ensign Lynch thought he saw a dim shape beyond his victim and was alert when another surfaced I-boat shot four torpedoes at him. He slipped between the torpedo tracks, but could do nothing about retaliating, because he had emptied his tubes. He had to let the second I-boat go. Postwar assessment gives Ensign Lynch a definite kill on this submarine. The same Christmas Eve, two other PTs from the Oro Bay base sank two barges full of troops. Ensign Lynch’s torpedoing of the submarine—the first combat victory of the PT fleet in New Guinea waters—was a spectacular triumph, but the sinking of two barges was much more typical of the action to come. The terrible attrition of ships in the Guadalcanal fight had left the Japanese short of sea transport. Besides, Allied airmen made the sea approaches to New Guinea a dangerous place for surface craft in daylight. Nevertheless, the Japanese had to find some way to supply their New Guinea beachheads by sea or give them up, so they began a crash program of barge construction. The barges were of many types, but the most formidable was the _daihatsu_, a steel or wooden barge, diesel powered, armored, heavily armed with machine guns or even with automatic light cannon. They could not be torpedoed, because their draft was so shallow that a torpedo would pass harmlessly under their hulls. They could soak up enormous amounts of machine-gun fire and could strike back with their own automatic weapons and the weapons of soldier passengers. A single _daihatsu_ could be a dangerous target for a PT. A fleet of _daihatsus_, giving each other mutual fire support, could well be too much to handle even for a brace of coordinated PTs. The naval war around New Guinea became a nightly brawl between _daihatsu_ and PT, and the torpedo function of the PT shriveled. Eventually many of the boats abandoned their torpedo tubes entirely and placed them with 37-mm. and 40-mm. cannon and extra 50-caliber machine guns, fine weapons for punching through a _daihatsu’s_ armor. The PT in New Guinea gradually changed its main armament from the torpedo—a sledge-hammer type of weapon for battering heavy warships—to the multiple autocannon—a buzz-saw type of weapon for slicing up small craft. At the Buna-Gona-Sanananda battlefield, the Japanese were dying of starvation. It was the story of Guadalcanal again—with supply from the sea cut off by aggressive American patrols, the emperor’s infantry—no matter how desperately brave—could not stand up to a long campaign. The night between January 17th and 18th, the _Roaring Twenty_ (PT 120) caught three barges trying to slip out of Sanananda. The PT recklessly took on all three in a machine-gun duel, sank two of them, and set the third afire. PT sailors were the first to know that the end had come for the Japanese ashore, because the barges were loaded with Japanese officers trying to slip away from their doomed men. Next day Sanananda fell to the Australians.