A tragic underwater disaster unfolded off the coast of Egypt on Thursday morning when a tourist submarine sank in the Red Sea ...

North Korea revealed Saturday it is building a nuclear-powered submarine — a weapon that experts say would be “absolutely threatening to [South Korea] and the US.” Images showed Kim Jong Un ...

North Korea unveiled for the first time a nuclear-powered submarine under construction, a weapons system that can pose a major security threat to South Korea and the US. State media on Saturday ...

while compressed air valves introduce compressed air to bring the submarine to the surface. Safety valves prevent overpressure, and check valves prevent water from flowing back into the tanks.