Naval mine ship, HMHS "Britannic", which was the sister ship of the RMS "Titanic." During World War II, the U-boat fleet, which dominated much of the battle of the Atlantic, was small at the beginning of the war and much of the early action by German forces involved mining convoy routes and ports around Britain. German submarines also operated in the Mediterranean Sea, in the Caribbean Sea, and along the U.S. coast. Initially, contact mines (requiring a ship to physically strike a mine to detonate it) were employed, usually tethered at the end of a cable just below the surface of the
Wreck of the RMS Titanic D. Michael Harris and Jack Grimm had failed to find "Titanic" but their expeditions did succeed in producing fairly detailed mapping of the area in which the ship had sunk. It was clear that the position given in "Titanic"s distress signals was inaccurate, which was a major expedition difficulty because it increased the search area's already-expansive size. Despite the failure of his 1977 expedition, Robert Ballard had not given up hope and devised new technologies and a new search strategy to tackle the problem. The new technology was a system called "Argo / Jason". This consisted of a remotely controlled