Deep Navigation Colliery Deep Navigation Colliery Deep Navigation Colliery was a coal mine in South Wales, that operated from 1872 until 1991. Located next to the co-developed village of Treharris in the borough of Merthyr Tydfil, on development it was the deepest coalmine in South Wales Coalfield by some . Producing the highest quality steam coal, it powered both the Cunard passenger steamers RMS "Mauretania" and RMS "Lusitania" in their successful attempts at the Blue Riband prize for the most rapid Atlantic Ocean passage. The mine is also thought to have been one of several locally that provided coal to the RMS Titanic;
Deep sea true...(Below 200 meters) lies the largest habitat on earth. In 1960, the Bathyscaphe "Trieste" descended to the bottom of the Mariana Trench near Guam, at , the deepest known spot in any ocean. If Mount Everest (8,848 metres) were submerged there, its peak would be more than a mile beneath the surface. The "Trieste" was retired, and for a while the Japanese remote-operated vehicle (ROV) Kaikō was the only vessel capable of reaching this depth. It was lost at sea in 2003. In May and June 2009, the hybrid-ROV (HROV) "Nereus" returned to the Challenger Deep for a series of