KITTERY — Top state and federal officials from Maine and New Hampshire took advantage of a visit by a Navy admiral Friday to make the case, one more time, for keeping the Portsmouth Naval Shipyard off a list of military bases that could be closed. "It was an opportunity once again for us to showcase and champion the finest shipyard of its kind in the U.S.," Sen. Olympia Snowe, R-Maine, said after meeting with the admiral. "We want to make sure that every office in the Navy has an understanding that this is an irreplaceable asset."

Snowe and Sen. Susan Collins, R-Maine, were part of a delegation that accompanied Adm. Kirkland Donald on a tour and inspection of the shipyard. The delegation also included Maine Labor Commissioner Laura Fortman and New Hampshire's governor and two senators. An aide to U.S. Rep. Tom Allen, D-Maine, also attended.

Donald is director of the Navy's nuclear propulsion program and visits submarine repair yards as part of a periodic certification. His visit Friday included a tour and a presentation by employees who touted the shipyard's record of quality and safety.

Donald did not attend the post-tour news conference with elected officials, and made no public statements about the visit or the future of the shipyard.

The visit came at what may be a critical moment in the history of the 204-year-old shipyard. A Navy panel that is preparing recommendations for the closure of bases could submit its preliminary list to the Defense Department as soon as next week.

Defense Secretary Donald Rumsfeld plans to save money by closing as many as 425 military bases - one quarter of the bases nationwide. He must submit a comprehensive list of proposed closures by May 16 to a nine-member review committee to be appointed soon by President Bush.

Advocates for the Kittery shipyard are worried because of several factors that could be disadvantages in the evaluation process.

The Defense Department plans to scale back the construction of submarines from two to one per year, and Portsmouth is one of four remaining Navy shipyards that overhaul and repair nuclear submarines.

Some experts predict that the military may give priority to West Coast bases and shipyards, to shipyards that serve multiple military functions, and to bases geared more to modern threats such as terrorism.

The high-power delegation that lobbied Donald on Friday focused instead on the advantages that they say will keep the shipyard off any closure list.

They praised the shipyard as the premier facility for overhauling the subs, consistently finishing projects ahead of schedule and under budget, and developing new technologies and methods that set standards throughout the Navy.

"This is the lowest-cost, highest-quality shipyard that the Navy has," Collins said.

Retired Navy Capt. William McDonough, who commanded the shipyard in the 1970s and now leads a group that is working to keep it open, said Donald is not directly involved in the decisions about which bases will be on the closure lists.

But, he said, the chance to show off the work done here to Navy brass can only help.

"He knows that the shipyard turns out its submarine products in less time than anyone else," McDonough said. "I'm sure if he has any opportunity, he'll put in a good word for us."