BOSTON, Mass. — Two Maine islands with lighthouses will be sold by online bid in late May or early June. The General Services Administration (GSA) has taken possession of Boon Island and Halfway Rock from the U.S. Coast Guard and expects to start bidding at $5,000.

“When the Coast Guard deems them no longer necessary, they give them to GSA,” said Patrick Sclafani, a spokesman for the federal agency.

GSA worked with the National Park Service and the Department of the Interior over the last few years to consider applicants to take over the properties, he said. Those applicants generally include nonprofit organizations and those dedicated to education, he said, and they must comply with various restrictions related to maintaining structures. At the end of that process for Boon Island and Halfway Rock, no successful applicants were identified, so the purchase-by-bid phase has begun.

Bidding is expected to begin on May 15 with a minimum of $5,000 for each island. Bidders should visit http://realestatesales.gov or http://propertydisposal.gsa.gov.

for more information.

Both lighthouses were added to the National Register of Historic Places in 1988. Boon Island, the site of the 1710 shipwreck of the Nottingham Galley that resulted in the crew eating a dead comrade, is in the town of York about six and a half miles off the coast. The light was established in 1855 on a 133-foot tapered tower built from ashlar granite, according to the website, LighthouseFriends.com. A shed and the remnants of a boathouse remain on the tree-less island, which is just 14 feet above sea level, along with the tower.

Halfway Rock is so named because it is about halfway between Cape Elizabeth and Cape Small, near Popham Beach. In February 1861, the British ship Boadicea collided with the island, killed all aboard. Eight years later, the federal government authorized $50,000 to build a lighthouse there.

But it wasn’t until 1871 that the light station, which features a 76-foot granite block tower, was completed. Today, the rocky, tree-less two-acre island includes a wooden boathouse, along with the tower.

Both lights will continue to be operated by the Coast Guard.

Sclafani said if a high bidder does not elicit any other bids over a 24-hour period, GSA then verifies that the bidder is qualified to pay and meets the historic deed covenants that come with the property. The bidding process may continue over weeks, he said, if there are active, competing bidders.

Proceeds from a public sales go back into the Coast Guard’s aid to navigation fund that pays for fog horns, lights, battery cells, solar panels, etc.

To date, more than 100 lighthouses have been sold or transferred out of federal ownership, with 66 transferred at no cost to preservationists, and 37 sold by auction to the public.