Mike Rounds

Keel laying held in Rhode Island for stealthy Navy submarine

Officials representing the Navy and shipbuilders gathered with politicians Monday to praise a $2.5 billion submarine that they say will be the stealthiest vessel patrolling the oceans for the U.S. military — the South Dakota.

It will have quieter machinery, a coating on its hull to further eliminate noise and sonar panels to better detect and track other submarines, Rear Adm. Michael Jabaley said during the ceremony in Rhode Island, where the submarine is being built. Those new modifications represent about $115 million of the cost, the Navy says.

"With the undersea environment constantly changing and becoming more crowded with capable threats, the Navy has...