The submarine USS Hawaii yesterday completed a month-long, $2.5 million refit at the Pearl Harbor Naval Shipyard, the first work there on a Virginia-class sub.

It took months of preparation before the Navy's newest and most advanced submarine could enter Pearl Harbor's dry dock 2 on March 30 for routine inspections and repairs.

As Pearl Harbor's first Virginia-class submarine, the Hawaii presented new challenges for shipyard crews used to working on older, smaller Los Angeles-class boats.

“;Docking Hawaii was a tremendous milestone for Pearl Harbor Naval Shipyard and our future availabilities to support Virginia-class submarines,”; said Lt. Lorenz Tate, shipyard docking officer.

Tate and dockmaster Sonny Deltoro went to the East Coast last month to watch as Electric Boat, one of the builders of Virginia-class submarines, docked a similar sub.

“;The entire shipyard was very excited to dry-dock USS Hawaii and validate the hard work and dedication of the many people involved in this evolution,”; said Capt. Greg Thomas, shipyard commander. “;The successful execution was the fruit of their labor, earned from careful and relentless preparation.”;

The Navy said a special project team was dedicated strictly to the USS Hawaii's dry-docking because of the complexities of accommodating a new class of vessel.

In August 2008, the shipyard conducted a practice exercise followed by an evaluation session. Several weeks before the Hawaii entered the dry dock, two conferences involving all of the labor unions involved in the maintenance operation were held.

“;The pre-trades conference was an above-and-beyond effort we put forth for Virginia-class docking,”; said Cmdr. Leonard Laforteza, the Virginia-class submarine program manager. “;It was important to address potential issues before the official all-trades conference.”;

As an added precaution, Navy divers were present in the dry dock during the actual docking, a measure not normally required for Los Angeles-class submarines.

The Navy is gradually replacing its 6,000-ton, 362-foot-long Los Angeles-class subs with the 7,800-ton, 377-foot Virginia-class vessels.

The USS Hawaii arrived at Pearl Harbor on July 23. It was followed by the USS Texas in October. The USS North Carolina will arrive this summer. Each cost $2.3 billion.

The Navy said that before the end of the year, the Hawaii and Texas will depart from Pearl Harbor on their initial regular-length deployments.

Seventeen of the 30 Pacific Fleet's attack submarines are home-ported at Pearl Harbor, and each of these contributes about $17 million a year to the economy in Hawaii, according to Gov. Linda Lingle.