WILMINGTON - Master Chief Barry Swofford joined the Navy in the 1980s, volunteered for the "silent service" and got down to work stalking Soviet submarines.

"That was the threat. That was the job," Swofford said.

But two decades later, the Russian submarines Swofford spent a career chasing don't pose much of a threat. Terrorism is the nation's primary concern, and fighting it is the mission he'll take to sea aboard his new assignment and the Navy's latest sub: the USS North Carolina.

The Navy commissioned the North Carolina on Saturday, the fourth $2.4 billion Virginia-class vessel to join the service's fleet of more than 50 submarines. It was designed to attack land and sea targets with cruise missiles and torpedoes, or sail into shallow waters to monitor enemy transmissions or drop off SEAL teams.

Speaking at the commissioning ceremony at the state port in Wilmington, Navy Secretary Donald Winter said the United States faces many challenges in the wake of the Sept. 11 terrorist attacks. With 70 percent of the world's surface covered by water and 90 percent of international trade transported by sea, he said the North Carolina is the perfect weapon to meet them.

"We must remain vigilant and be prepared to face the challenges that risk surprising us in the decades ahead," Winter said. "With USS North Carolina, the nation has made an investment in our safety and in our peace. She now joins the world's greatest Navy and will be cast into a wide range of missions."

The sub is the fourth vessel to carry the USS North Carolina name. The most famous is the World War II battleship now berthed on the Cape Fear River not far from Saturday's commissioning ceremony.

Linda Bowman, the sub's sponsor and wife of retired Adm. Frank L. "Skip" Bowman, gave the first order to the crew to "man our ship and bring her to life." Crew members in dress white uniforms raced from behind the more than 5,000 spectators to the sub. The masts and radar dish rose from the submarine's black tower, and the North Carolina let out a long blast from its horn.

Silent no more

The sub was transformed from a "silent hull" to a "fully alive warship."

Built in Virginia, the North Carolina is 337 feet in length, weighs in at 7,800 tons and can operate at more than 25 knots when submerged. It will based at the Navy's New London submarine base in Groton, Conn., and the crew of about 140 will be commanded by Capt. Mark Davis.

The submarine is the sixth on which he has served. "The previous ones pale in comparison to the North Carolina," Davis said.

The new sub is piloted using a joystick, and most of the controls on the sub's bridge are touch screens. The boat doesn't have a periscope with traditional optics. Instead, an extendable photonics mast is packed with high-resolution cameras and infrared sensors.

One of the biggest innovations: an expanded "lockout trunk" at the front of the submarine that allows a nine-man SEAL team to dive to and swim from the boat without requiring it to surface or stop. A computer keeps the submarine level while submerged, making it easier for the teams to deploy. The sub also has a docking area for a mini sub.

Versatility a strength

Lt. Cmdr. Andy Hertel, the sub's executive officer, said the North Carolina is far superior to any the Navy has previously sent to sea because of its ability to perform a variety of missions.

"The flexibility is designed into the ship," said Hertel, who served tours on two other submarines before coming to the North Carolina.

The North Carolina's focus on executing close-to-shore stealth missions is a departure from submarines' past missions of matching wits with Soviet submarines in deep ocean waters. Swofford said the sailors now take pride in delivering SEALs or intercepting radio transmissions undetected.

"If we can be a part of 'taking care' of the enemy, then that is something we can use to motivate our sailors," Swofford said.