Wreck Discovered Near Yap The USS Mississinewa (AO-59) -- believed to be the first and only U.S. ship to be sunk by kaiten, or suicide torpedo -- was discovered April 6 at the bottom of Ulithi Lagoon, about 100 miles northeast of the main island of Yap. The 553-foot-long oiler had been missing since it went down on Nov. 20, 1944. 50 sailors were killed when the 24,400-ton vessel was struck by what historians believe was a suicide torpedo operated by Lieutenant Sekio Nishina, co-inventor of the kaiten. The ship was discovered on its port side in 120 feet of water by a team of three divers from the San Francisco Bay Area. The search team consisted of Lewis "Chip" Lambert, his wife Pam Lambert and Pat Scannon, who used old photos, depthfinders and GPS to locate the wreck. Several previous searches failed to find the ship, which had been missing for almost 57 years. The sinking of the Mississinewa was one of the most significant Japanese naval triumphs of World War II. Four other Japanese kaitens were destroyed by U.S. Forces before hitting their intended targets in Ulithi Lagoon at the same time. In addition to the Mississinewa, there are about 20 U.S. Navy landing craft scuttled in Ulithi Lagoon. Don't pack your dive bag just yet, however. The wreck has been declared off limits to scuba diving pending discussions between Yap leaders and the U.S. Navy.