SS United States appears ghostly in photo from voyage to become artificial reef

PHILADELPHIA - It's been a week since the SS United States left its Philadelphia pier for the last time after it was sold to a Florida county to become part of an artificial reef.

A fleet of tugboats dragged the historic ocean liner down the East Coast and around Florida into the Gulf of Mexico towards its final destination in Mobile, Alabama.

The nearly 1,000-foot ship was purchased by Okaloosa County, Florida as part of a plan to create the world's largest artificial reef. 

The backstory:

Christened in 1952, the SS United States was once considered a beacon of American engineering, doubling as a military vessel that could carry thousands of troops. 

On its maiden voyage, it shattered the transatlantic speed record in both directions, when it reached an average speed of 36 knots, or just over 41 mph.

The ship crossed the Atlantic in three days, 10 hours and 40 minutes, besting the RMS Queen Mary's time by 10 hours. To this day, the SS United States holds the transatlantic speed record for an ocean liner.

She became a reserve ship in 1969, spending her retirement years on Philadelphia's Delaware waterfront.

After several different plans for the ship over the years fell through, it was sold last to Okaloosa County, Florida to become part of the world's largest artifical reef.

With help from tug boats, the ocean liner was pulled down the Delaware River last Friday and out to sea where it voyaged down the East coast and around Florida.

Dig deeper:

Since its departure, the SS United States has been spotted by people on land as it continues to head south.

A photo taken from one of the tug boats pulling the historic ship shows an eerie nighttime image of the historic ship.

A photo taken from one of the tug boats pulling the historic ship shows an eerie nighttime image of the historic ship.

A powerful spotlight illuminated the ship in darkness as it rounded Florida near the Keys.

What's next:

After making a stop in Mobile, Alabama, for repairs, the historic ship will reach its final destination in Destin, Florida, where it will be sunk to become part of the world's largest artificial reef. 

The repairs are estimated to take as long as 6 months to a year.

What you can do:

If you want to keep up with the ship's progress, you can track its journey online.