The Navy will be moving additional nuclear attack submarines to Pearl Harbor, San Diego and Washington state as part of a redistribution of submarine forces from the Atlantic to the Pacific, it was announced yesterday.

The shift, which will bring six additional subs to the Pacific and will mean 18 subs at Pearl Harbor compared with 17 now, is the first sign of big changes ahead for the distribution of Navy assets, predicted Loren Thompson, a military expert at the Lexington Institute in Virginia.

"I think over time, we will see most of the naval fleet move to the Pacific Basin," Thompson said.

That includes an aircraft carrier strike group for Pearl Harbor, a move seen as too costly given current defense-budget constraints, but that is "almost inevitable," Thompson said.

The submarine-basing plan is expected to bring to Hawai'i more than one of the Navy's new Virginia-class attack submarines, which have the capability to operate in shallow waters and drop off Navy commandos.

"I think the bottom line here is the shift of submarines to the Pacific is just the beginning of a broader move by the Navy fleet," Thompson said.

The submarine reorientation by the Navy, which has 28 attack subs on the East Coast and 25 in the Pacific, will begin as early as July 2007, Navy officials at the Pentagon said.

By 2010, the shift will result in 21 subs in the Atlantic and 31 in the Pacific. The number of ballistic-missile submarines — nine in the Pacific and five out of King's Bay, Ga. — will remain unchanged.

The reorganization reflects the Pentagon's decision, recently outlined in the 2006 Quadrennial Defense Review, to position 60 percent of its submarine force in the Pacific and 40 percent in the Atlantic.

"The (Navy) is continuing its shift from a one-size-fits-all notion of deterrence toward more tailorable approaches appropriate for advanced military competitors, regional (weapons of mass destruction) states, as well as nonstate terrorist networks," the Navy said in a statement.

Pearl Harbor has 17 Los Angeles-class attack submarines. Although the number called for under the Navy plan is 18, that doesn't mean the addition of a single submarine.

"It's not just simple math here. It's not just one for one," said Lt. Cmdr. Jeff Davis, a spokesman for Pacific Submarine Forces at Pearl Harbor.

Some subs will be retired or are being based elsewhere.

The USS Honolulu, stationed in Pearl Harbor for 21 years, will be feted with a farewell ceremony on April 15 before its final western Pacific deployment. After that, it will cruise to Washington state for decommissioning.

The USS Buffalo, meanwhile, is expected to report to Guam next year to replace the San Francisco, which was damaged on Jan. 8, 2005, when it slammed into a mountain 525 feet below the surface. A 24-year-old sailor was killed and 97 sailors were injured.

That means at least several replacement subs will be based at Pearl Harbor as part of the Navy's plan for 18 of the vessels here.

Navy officials in Washington yesterday said the names of submarines being reassigned will be released at a future date.

More than one Virginia-class submarine is expected to be home-ported at Pearl Harbor, starting with the USS Hawai'i, the third in its class and among the quietest subs in the world. The 377-foot Hawai'i will be commissioned in 2007.

Guam has three attack submarines, and that number will remain the same, the Navy said.

"We continue to think that three is about the right number for Guam based upon the factors that go into it," Davis said. "Strategic location is one factor, but so are infrastructure and the ability to do maintenance, the ability to do repair."

San Diego, with four of the 360-foot Los Angeles-class subs, would gain three more attack subs. Washington state has one of the submarines now and will receive two more.

Submarine bases at New London, Conn., and Norfolk, Va., will see a drop in subs from 28 to 21.

The Lexington Institute's Thompson said the submarine movement is a belated recognition of a changing world.

"I think what you can read into it is it may take a generation, but eventually, the military figures out that times have changed, and we don't need to worry about the Soviets anymore," he said. "We spent most of the Cold War preoccupied with the North Atlantic, and now there is a shift of focus to the western Pacific and northern Indian Ocean."

The Quadrennial Defense Review, recognizing the shift in trade from the Atlantic to Pacific and the growth of military power in countries such as China, called for a "greater presence" in the Pacific.

"Accordingly, the Navy plans to adjust its force posture and basing to provide at least six operationally available and sustainable carriers and 60 percent of its submarines in the Pacific," the plan said.

In June, three U.S. aircraft carriers will conduct war games in the western Pacific; in July, a carrier will participate in Rim of the Pacific naval exercises; and in August, an Atlantic Fleet carrier will conduct training in the Pacific, Navy officials said.

The $2.2 billion cost to station an aircraft carrier in Hawai'i, and overcoming the politics of moving a carrier from the Atlantic, were given as reasons why Pearl Harbor — much closer in sailing time to Asia than the West Coast is — hasn't so far been named to get a flattop.

"At some point here," Thompson said, "the Navy's going to have to explain what the value of having aircraft carriers is on the East Coast, when most of the threats are in the western Pacific and northern Indian oceans."

Thompson said two-thirds of an attack submarine's mission days are devoted to intelligence-gathering, and the subs can do so undetected off countries such as China and North Korea.

China also has bought "very quiet" Kilo-class diesel-electric submarines from Russia, is building a range of other submarines and is certain to outnumber the U.S. fleet in the future, Thompson said.

Reach William Cole at wcole@honoluluadvertiser.com.