The Navy is canceling a long-delayed overhaul of the USS Boise after costs ballooned to nearly $3 billion, with Secretary of the Navy John Phelan saying the submarine no longer made financial or strategic sense to repair.

One of the youngest Los Angeles-class nuclear attack submarines will be inactivated after waiting more than a decade for an overhaul, the Navy announced on Friday. USS Boise (SSN-764), currently in a drydock at HII Newport News Shipbuilding,

China's submarine force has typically focused on patrolling the shallow littoral waters of the South China Sea, but its new submarine is built for more.

Unlike your car, a submarine cannot use GPS to reach its destination, as the technology doesn't work underwater. Here's how they navigate instead.

British and Norwegian militaries led a weekslong operation to deter Russian submarines in the North Atlantic, the U.K. military said.

Some of the most powerful weapons in history never had to be used. Submarines have quietly reshaped warfare by doing

British defence minister says the operation did not find evidence that Russia had damaged undersea infrastructure.

Although exact numbers are difficult to pin down, estimates suggest Iran's navy has a fairly large number of subs in its fleet that span across four classes.

Historic submarines are surprisingly similar to those deployed by today's Navy and can provide an unprecedented look into modern combat at sea.

John Healey, the defense secretary, said the vessels were gathering information about undersea pipelines, and said he believed President Vladimir V. Putin “would want us to be distracted by the Middle East.