Restoration complete, ‘Old Ironsides’ returns to the water

In this Oct. 9, 2014, file photo, Secretary of State John Kerry walks down the gang plank of the USS Constitution, "Old Ironsides," during a visit to the U.S. Navy's oldest commissioned ship in Boston. The USS Constitution, the world's oldest commissioned warship still afloat, is set to depart from its berth at the Charlestown Navy Yard with about 500 specially-invited guests Friday, Oct. 17. (AP Photo/Stephan Savoia, File)

BOSTON (AP) — The world’s oldest commissioned warship still afloat is returning to Boston’s waters.

The USS Constitution is undocking Sunday, marking the end of restoration work that started two years ago.

“Old Ironsides” enters dry dock about every 20 years for below-the-waterline repairs. The most recent work included installing 2,200 new copper sheets and replacing 100 hull planks and gun deck waterways.

Officials say the dry dock at the historic Charlestown Navy Yard will be flooded, and the ship will be towed out and will float into Boston Harbor.

The ship, which was launched in 1797, earned its famous nickname notching victories in the War of 1812.

Once the vessel is refloated, it will be temporarily docked at a nearby pier until September, when it will reopen for public tours.