PEARL HARBOR — The submarine USS Ohio, loaded with SEAL commandos and Tomahawk cruise missiles, is wrapping up its maiden deployment after crisscrossing the Pacific, conducting exercises and real-world missions as a new type of underwater stealth weapon.

The nuclear submarine, converted from a ballistic missile "boomer" to a special operations platform, spent the past fourteen months away from home, with most of that time at sea and minimal maintenance in Guam.

Its maiden voyage began at Naval Base Kitsap in Washington state on Oct. 14, 2007. Commanding officer Capt. Dennis Carpenter, who's had the sub for the past 4 1/2 months, said the ship didn't disappoint.

"Just the reliability of the systems really impressed me," Carpenter said last week during a weeklong stop in Hawai'i. "As many years as I've had in, to actually have the submarine deployed for that long and to be able to keep operating as well as the ship did, I thought it was extraordinary."

The Ohio was built as one of 18 ballistic missile submarines. But under the Strategic Arms Reduction Treaty, or START II, agreed to in 1992, the U.S. was limited to 14 ballistic missile subs starting in 2002.

Rather than decommission four submarines, each of which could carry 24 Trident missiles, the Navy decided to convert the oldest four — Ohio, Michigan, Florida and Georgia — into guided missile subs with extra room for SEALs and Tomahawk missiles.

The Ohio returned to the fleet in February 2006 after a $250 million nuclear reactor refueling and a $750 million conversion.

The former "boomer" carries 15 officers and 140 enlisted men, but it's been outfitted with 66 extra beds, or "racks," for commandos. It also can carry 154 Tomahawks in canisters of seven each that are loaded into the former Trident missile tubes. All ballistic missiles have been removed.

Carpenter said he had about 66 SEALs aboard, including some from SEAL Delivery Vehicle Team 1 at Pearl Harbor. The commandos can be hosted on the converted subs, known as SSGNs, for up to 90 days. Up to 100 can be accommodated for about 30 days.

"Anywhere in the world, a potential adversary has to face (the fact) that an SSGN can be there in an unknown location and within a short amount of time have Tomahawk cruise missiles, 100 or more, coming his way," Carpenter said. "That's got to make somebody pause."

Such a force also can help shore up allies in the western Pacific, Carpenter said.

At 560 feet, the converted ballistic missile subs are nearly 200 feet longer than the 15 Los Angeles-class attack submarines that are based at Pearl Harbor.

On the latest leg of the deployment, the Ohio completed SEAL training using the two "dry deck" shelters on its back, which launch SEAL delivery vehicles.

The sub visited South Korea, the Philippines, Japan and Guam. Carpenter said he made the Guam-to-Japan transit "several times" just under his command.

Guam is used as a forward-deployed base for crew swaps and whatever maintenance is needed. Each crew usually is on the sub for three to four months.

The Ohio conducted three unspecified "national tasking missions" and earned two Navy Expeditionary Medals.

Carpenter said more than 80 percent of the sub's 14 months out was spent at sea, with the remaining time devoted to port visits and maintenance.

"I don't know anybody that's gone out for that long," he said.

Carpenter said there is berthing space for the SEALs "and a ton of exercise equipment, so those guys on board were pretty much working out and eating a lot of food."

The mission mix between the sub crew and the SEALs made for a more interesting tour, Carpenter added.

Michigan, another of the converted submarines, also recently spent time in Pearl Harbor.

Navy Times reported that the one-of-a-kind Advance SEAL Delivery System mini-sub based at Pearl Harbor was supposed to deploy in November aboard the Michigan, but a battery fire on the smaller sub prevented the mission from taking place.

Carpenter said the Florida is in the 5th Fleet operating area, which includes the Middle East, and is "doing real-world missions," while the Georgia has completed its conversion.