Receiving orders to penetrate shallow, hazard-filledBlair, p.147. Lingayen Gulf and attack hostile shipping, she entered the gulf just before dawn on 22 December. At 06:45, she sighted an enemy convoy of four transports, escorted by two destroyers. Waiting for the range to drop to a very short , at 07:10, she fired four bow tubes — all misses. As she reloaded, the enemy destroyers closed in, pinging, but no depth charges came. At 07:58, she launched two torpedoes at an anchored enemy cargo ship. Less than a minute later, the 5445-ton Hayo Maru blew up. Enemy destroyers again closed the submarine, and she went "deep", to , and lay doggo as depth charges rained, none close.Blair, p.148. From 08:04 to 09:30, the S-boat ran silent, using evasive tactics. At 09:30, she grounded on the muddy bottom; she remained there most of the day, destroyers, joined by small boats, continuing to search, without success. At 21:30, the hunted submarine began efforts to clear by backing. During the maneuvering, her port propeller was damaged; but, by 22:01, she was free and underway for the Hundred Islands area on the western side of the gulf. S-38 surfaced to change the air and charge batteries, then dove at dawn, remaining on the bottom all the next day, giving her crew a rest.
