Taiwan unveiled its first-ever domestically built submarine on Thursday, an accomplishment the island democracy’s leader hailed as a significant milestone as Taipei works to boost its military ...

“Submarine caves are a treasure trove of useful substances that have yet to be known,” Ise said. PITCH-DARK EVEN IN DAY Expeditions inside submarine caves carry a constant element of danger.

On Dec. 17, 1917, the U.S. submarine USS F-1 was lost at sea during a training accident off the coast of California, killing 19 crew members on board.