The U.S. Navy hopes a high tide due to reach Hawaii early Saturday will enable it to refloat a 9,600-ton warship that ran aground off seaside Honolulu International Airport. An initial effort by Navy tugs early Friday to free the guided missile cruiser USS Port Royal was unsuccessful. The $1 billion ship ran aground Thursday night while carrying guests that included a rear admiral. «We're certainly working on bringing to bear the resources we have to move her off the current position. We're still putting that plan together,» said Capt. W. Scott Gureck, a spokesman for U.S. Pacific Fleet. Divers and the salvage ship USS Salvor would try to tow the 567-foot (173-meter) vessel, the Navy was quoted as saying by Associated Press. The cause of the grounding on the sandy bottom and the extent of damage to the vessel were under investigation.