PHILADELPHIA — A U.S. warship that survived the Spanish-American War and World War I and has been on the Philadelphia waterfront for a half-century might wind up in a watery grave — sunk deliberately to form an artificial reef off New Jersey.

The Independence Seaport Museum says it can no longer afford the upkeep of the cruiser Olympia, the last surviving vessel from the 1898 Spanish-American War, which is now docked at Penn's Landing. At least $20 million is needed to tow, restore, interpret and endow the deteriorating vessel, interim museum President James McLane said.

The museum and the Navy have already checked with officials of New Jersey's Artificial Reef Program on the possibility of sinking the 5,600-ton ship. The vessel will be open until the end of September and then closed.

"Another option would be scrapping Olympia," McLane said. "But the Navy has told us that 'reefing' is better because it would allow divers to go down on it and would preserve Olympia."

The possibility dismays Harry Burkhardt, president of Friends of the Cruiser Olympia, which is trying to raise money to preserve the ship.

"The Liberty Bell has a crack in it, but we don't melt it down. The Statue of Liberty turned green with corrosion, but we don't throw it away," he said.

The Olympia was state-of-the-art when it led five other U.S. warships into Manila Bay in the Philippines on May 1, 1898. Under Commodore George Dewey's command, the U.S. fleet destroyed 10 Spanish cruisers and gunboats in hours without losing an American life. The Olympia spent World War I in the Atlantic Ocean and brought remains of the Unknown Soldier home from France in 1921.