The Pentagon, in search of rest and recreation destinations for U.S. troops in Saudi Arabia, has chartered a luxury cruise ship for a fee of $31 million to provide brief Persian Gulf getaways for desert-weary soldiers, defense officials said yesterday.

The military also is searching for a second cruise ship after a smaller vessel it planned to lease for $23 million failed its safety inspection yesterday, officials said.

The Cunard Princess -- complete with swimming pool, movie theater, whirlpools and beer -- is expected to arrive in the Persian Gulf and start receiving its military guests before Christmas. About 800 servicemen and women at a time will be rotated aboard the ship for three or four days of fun and air conditioning, authorities said.

Military officials yesterday gave only sketchy details of their R&R plans for the ship, but said it will not be open to visits from relatives.

Some Pentagon officials have sharply criticized the Army cruise ship idea on grounds that the soldier-packed vessel could become a terrorist target. One senior official described the ship as a potential "Beirut barracks," a reference to the 1983 terrorist bombing of the Marine barracks that killed 241.

The Navy will provide protection for the vessels, officials said.

When asked about the military contract, a spokesman for Cunard Lines, which also operates the Queen Elizabeth II, said, "We've cancelled all bookings on the Cunard Princess for the next six months. That's all I can say."

The Army plans to charter the Cunard vessel and a second ship for six months, officials said.

Army officials decided on the charter approach to R&R to help alleviate the shortage of facilities in Saudi Arabia and to circumvent some Islamic restrictions on alcohol and entertainment. The military also is providing limited recreational centers in Saudi Arabia.

Even so, only a small percentage of the 430,000 U.S. personnel scheduled eventually to be posted in the region will ever have access to the R&R services, some officials noted.

The "Berlitz Complete Handbook to Cruising" describes cabins aboard the Cunard Princess as "small and compact, with tinny metal fixtures, very thin walls and little closet space." The guidebook adds, however, "This ship provides a very comfortable first-cruise experience at an excellent price, to well-chosen destinations."

Senior Army officials first floated the cruise ship idea almost two months ago during trips to Saudi Arabia. Shortly after public mention of the plan by one Army leader, U.S. troops at one Saudi air base posted a sign-up sheet on the wall for the "Love Boat R and R Cruise." A note at the top of the list asked that potential customers designate "deck preference -- promenade or lido."