Once more the Sea King, struts and wires screaming vengeance, swept down. Again Tim scored a hit, the blast from the third bomb leveling the stubby masts and the funnel. The deck of the ship was strewn with wreckage and the _Iron Mate_ was definitely out of commission as far as any more fighting was concerned. Tim landed the Sea King inside the barrier of reefs and taxied alongside the _S-18_. "Splendid work," shouted Commander Ford, and the others in the crew were loud in their praise. Tim and Pat made the Sea King fast again at its moorings and rowed back to the submarine. In the distance the _Iron Mate_ was painfully limping away from the scene. CHAPTER TWENTY-TWO Trapped With the menace of the _Iron Mate_ definitely removed from their thoughts, the crew of the _S-18_ turned their full attention to the task of retrieving the treasure in the Southern Queen. Mess that noon was a hasty meal with Commander Ford and the chief divers, Charlie Gill and Russ Graham, taking just time enough to grab a sandwich and gulp a cup of hot coffee. There was a haze over the mainland and the air was heavy, surcharged with tension. The song of the Isle of the Singing Trees was high pitched and Tim would be glad to see the last of the dismal island. Plans for the dive down to the hull of the Southern Queen were completed. Members of the crew hurried to their stations, hatches were made fast and the warning bell echoed throughout the interior. Tim was in the diving compartment. Charlie and Russ had already donned their diving suits and entered the special compartment. Telephone cables, protected by a steel sheeting, ran into the main compartment, giving the divers instant communication with their helpers. Earl Bell was at the phones as chief assistant with Roy Gould standing by. Commander Ford hurried up. "Everything all set?" he asked Bell. "Charlie and Russ are ready and everything in the special diving compartment seems to be all right." "Tell them we're going down." Commander Ford hastened back to the control room. From the rear of the _S-18_ came the hum of the powerful electrics. Tim felt the submarine move slightly. They were going down, going to the bottom of the treacherous bay in search of a fortune in gold, a fortune which had been under water for eleven years. The special diving compartment in which Charlie and Russ were seated filled with water. Gently the _S-18_ eased toward the bottom, scarcely more than a foot at a time. Ten, twenty, thirty, forty feet they went down. Tim watched the gauges fascinated. The two divers, in their heavily armored suits, sat quietly in their compartment as the pressure increased with the depth.