HMAS Diamantina (K377) deepest known part of the Indian Ocean on 7 February 1960, which was named Diamantina Deep after the ship. Based in Fremantle, Western Australia, "Diamantina" remained in service as an oceanographic vessel until 1980; she briefly interrupted these duties in March 1963, escorting the royal yacht during Queen Elizabeth II's tour to Australia. "Diamantina" paid off from the RAN on 29 February 1980, and was the last World War II-era frigate to serve Australia. "Diamantina" was handed over to the Queensland Maritime Museum to be permanently berthed in the South Brisbane Dry Dock located on the Brisbane River at South
Oceanic trench Oceanic trench Oceanic trenches are topographic depressions of the sea floor, relatively narrow in width, but very long. These oceanographic features are the deepest parts of the ocean floor. Oceanic trenches are a distinctive morphological feature of convergent plate boundaries, along which lithospheric plates move towards each other at rates that vary from a few millimeters to over ten centimeters per year. A trench marks the position at which the flexed, subducting slab begins to descend beneath another lithospheric slab. Trenches are generally parallel to a volcanic island arc, and about from a volcanic arc. Oceanic trenches typically extend below