PEARL HARBOR_ The Navy plans to try a fourth attempt tomorrow to remove the USS Port Royal, the Navy warship that ran aground Thursday.

When high tide hits early tomorrow morning, tugboats will return to try to dislodge the guided missile cruiser that is stuck in 17 to 22 feet of water about a half mile off Honolulu International Aiport's reef runway.

The Navy plans to remove the ship's anchor and the chains, which will lighten the ship by about 40 tons and remove the 800-tons of sea water that is inside the hull to stabilize the ship, said Rear Adm. Joe Walsh, deputy commander of the U.S. Pacific Fleet. If none of these actions work to dislodge the ship, the Navy will consider dredging a channel behind the boat to help unloosen it.

When the Navy tried to dislodge the ship earlier this morning, it used a salvage ship, the USNS Salvor (T-ARS-52), a motor vessel the Dove and four Navy and three commercial tugboats tried to remove the ship during high tide.

"Although we had more horsepower, we were unable to pull the ship free," Walsh said. "We were only able to pivot the ship about 20 degrees.

"Our priorities have been and remain the safety of the crew, the safety of the ship and the safety of the environment. There have been no injuries associated with the grounding or our recovery efforts."

The larger tugboats and tow vessels used this morning provided more pulling power to nudge the 9,600 ton, 567-foot-long ship off the sandy and rocky bottom, but that wasn't enough. This morning the Navy began their redoubled effort at 1:30 a.m., but the ship remained aground after four hours of towing. The Navy's assessing its options on how to proceed.

The Navy is investigating the cause of the grounding and would not discuss any details of their investigation. The cost of removing the ship has not been determined yet, Walsh said.

Previous attempts on Friday and Saturday morning to refloat the ship were unsuccessful. Prior to yesterday's attempt. The Navy planned to remove fuel from the ship, but heaving seas prevented that from happening as the barge and ship were roiling into each other.

The ship is home ported at Pearl Harbor and was commissioned on July 9, 1994. The ship's hull is structurally sound and there has not been any fuel leaks or spills.

"We are working closely with both the U.S. Coast Guard and the state of Hawai'i to ensure all precautions are being taken should a release of fuel occur," Walsh said. "If we're unsuccessful tomorrow morning, we'll further lighten the ship."