A week later, she fired her stern tubes at a freighter and watched one hit forward of the bridge before going deep to evade depth charges from an escorting destroyer at which she had also fired. In March, "Seawolf" was hunting between Java and Christmas Island. On 1 April, she stealthily approached the anchorage at Christmas Island where the Japanese invasion force lay at anchor. "Seawolf" fired a spread at . Though "Seawolf" was credited with a sinking at the time, only one torpedo hit, causing significant damage to the ship, although not harming any of the crew. "Naka" was forced to return to Japan for repairs and was out of the war for almost a year. Unaware she had hit her target, "Seawolf" then underwent 7 hours of depth charge attacks. On 1 April, she attacked two cruisers. A violent explosion was heard, but no flames were seen. "Seawolf" ended her patrol on 7 April at Fremantle and received the Navy Unit Commendation.