Distance from Koror: 1.5 miles (2.4 km), 5-6 minutes by speedboat.
Level of Diving Experience: Intermediate to advanced level of dive experience. Wreck Diver Certification mandatory if penetrating the wreck. This dive requires careful monitoring of bottom time and air consumption.
Diving Depth Summary: The Ryuko Mary is sitting upright in 100 feet (30 m) of water, the deck is at 80 feet (25 m) and the superstructure is at 70 feet (21 m).
Visibility: Visibility varies at this site. The bottom of the bay is thick silt, if the tide is running the visibility can quickly drop to 5 feet (1.5 m), but on average the visibility is approximately 45-60 feet (15-20 m).
Location: On the northern shore of Ngargol Island, close to Palau Pacific Resort.
Type: Standard Type 1C 2500-ton Class Cargo Steamer ship.
Length: 321 feet (80 m)
Beam: 59.3 feet (18 m)
Tonnage: 2,750 tons.
Built: 1943 builder unknown
The Ryuko Maru was sunk during operation DESECRATE ONE on March 30-31, 1944 by a near miss bomb with a “delay fuse” that exploded on impact with the water. The bomb blew a hole in the ship’s side approximately 10 meters wide and 3 meters below the water line. She sank upright. More damage was done post-war by salvage operators when the engine and other machinery were removed.
Reef Formation: Sand/silt bottom.
Marine Life: The Ryuko Maru is covered with extensive coral growth. Large bushes of black coral can be found growing out of the rails, decks, and superstructures of the ship. Whip corals, hard coral, sponges, oysters and other sessile growth cover the rest of the ship. Tropical fish such as rainbow runners, fusiliers, anthias, jacks and lionfish make the Ryuko Maru their home.
Diving: There is no problem entering the forecastle, but the sediment is very thick and easily stirred up. Cargo holds one and two are empty and can be entered, but the sediment is thick here too. Amidships you can find two gun mounts, one of them has fallen down to the deck and the other rests on the flying bridge. Cargo hold three and four have no dividing bulkhead allowing the diver swim between them under the mast house. The poop deck is worth exploring; it is in fairly good shape and allows access to the steering compartment.
Fascinating Facts: The Ryuko Maru was known to be in Chuuk Lagoon on the last day of operation HAILSTORM, February 18, 1944. At the time she entered the harbor she was on fire, she was carrying survivors from the Tatsuha Maru and her cargo holds held a load of ammunition. U.S. codebreakers tracked the ship through intercepted messages sent by the Japanese command as she departed Chuuk for Palau.