Abstract: A welder and his helper were assigned to replace a 2.5-inch-diameter salt water ballast line in a starboard ballast tank. This work consisted of removing the old line with a cutting torch, cutting new holes through the bulkheads, installing the new pipes, and placing patches over the old holes. The two employees were both wet from working in a few inches of water and from perspiration. The welder was using a 225-ampere ac arc welding machine that was part of the ship's equipment and that was not approved for use in wet locations. While the welder, whose clothes and gloves were wet, was sitting on the wet inner surface of the tank, the electrode holder contacted his body. The welder was electrocuted.