China unveiled a high-tech, high-speed submersible unmanned surface vessel called Blue Whale on Monday ... and infrastructure inspections, including submarine cable maintenance.

In August 1941, during the execution of a combat mission in the southwestern part of the Peter the Great Bay, two small submarines of the Pacific Fleet, "M-49" and "M-63," went missing.

After the war, in the 1870s the Navy tested out another hand-cranked submarine, the Intelligent Whale. The tests were deemed unsuccessful. The sub is now on display at the National Guard Militia ...

The Blue Planet II Team from the BBC nature show was observing animals feeding on a whale carcass when the sharks attacked their submarine. A video posted on YouTube by BBC News shows the ...