Three days later, still on patrol. "Grapple" received more serious injuries—this time at the hands of a friend. Because of a mistake in Identification signals, (AM-315) opened fire on "Grapple" at a range of about 900 yards. Several shells fell short or exploded above the ship, but one 3" projectile hit just above the pilot house, killing 2 men, injuring 11 others, 3 critically, and doing extensive damage to pilot house and gun deck. After repairs at Sasebo, "Grapple" returned to Korea, making three more "flycatcher" patrols to protect U.S. ships operating off shore before returning to Pearl Harbor 9 December 1952. She then sailed for overhaul at Seattle, Washington.