Unless you're a military history buff, you may not have heard of the USS Nevada. But her story is pretty cool and she was recently pinpointed and observed on the sea floor just off of Hawaii's Oahu.
In service during both World War I & II and used during nuclear weapons testing at the Bikini Atoll, the ship's status as "unsinkable" was solidified as her crew managed to steam her out of port during the Pearl Harbor attacks. When the vessel was formally decommissioned it was used for target practice and took quite the assault before finally, finally sinking into the sea - where the rough area was known but the precise location unseen for decades.