The USS San Juan, the Navy's newest submarine, was commissioned Saturday during a ceremony picketed by anti-nuclear weapons demonstrators.

The nuclear attack sub, built by General Dynamics Corp., is the third U.S. Navy ship to bear the name San Juan, the capital of Puerto Rico.The vessel is 360 feet long, 33 feet wide and displaces about 6,900 tons of water when submerged. A so-called Los Angeles-class sub, the San Juan is designed to hunt and destroy enemy submarines.

About 10 anti-nuclear weapons opponents staged a demonstration outside the submarine base to protest the commissioning. There were no arrests, police said.