ANNAPOLIS, Md. — The Thomas Point Shoal Lighthouse on Chesapeake Bay has opened for tours for the first time in its history.

The 1875 Maryland landmark has been undergoing renovation and has long been a beacon to mark shallow water for fishermen and recreational boaters.

Henry Gonzalez, vice president of the U.S. Lighthouse Society, said the goal was "to restore it to how it looked in the early 1900s, 1901 through 1908, roughly. We have some good documentation from those years."

Tours began July 7, taking maritime history buffs on a boat ride to the bay landmark, which stands 43 feet above the water and is the only screw-pile lighthouse remaining in its original location in the bay.

Visitors can also use a new dock to gain access to the lighthouse and climb a narrow ladder on their way to the first floor of the building, which was designated a national historic landmark in 1999.

Fog-detection signal equipment and automation equipment still used by the Coast Guard and National Oceanic and Atmospheric Administration in a portion of the lighthouse is on view through a clear protective panel. The lighthouse remains an active weather station and navigational aid.

There are new windows and doors, but visitors also get to see the original kitchen and bedrooms used by lighthouse keepers. The interior remains in good shape. The old bottomless outhouse juts off one side.

The Coast Guard staffed the lighthouse until 1986, when Thomas Point became the last lighthouse on the bay to be fully automated.

The Annapolis Maritime Museum leads the tours.

The entire preservation program started in 2004 and is scheduled to be completed by 2009, Gonzalez said.

"In some areas, we're ahead of schedule," he said. "In some areas, we're pretty much on schedule."

Gonzalez said about 95 percent of the restoration is being done by volunteers. Companies have donated paint and shutters for the windows. He said the most challenging and costly part of the project is restoration of the foundation. Workers are repairing the badly corroded screw piles and steel framework.

Sherri Marsh Johns, an architectural historian with the lighthouse society, said a lot of work has been put into preserving the historical integrity of the building.

"I think we've been very successful in using new products to represent what was here originally," she said. "The rule is that you preserve all that you can."

The overall estimate for the cost of the renovation is roughly $500,000, Gonzalez said. About $300,000 has been raised so far.

The restoration is being conducted through a partnership between the city of Annapolis, the lighthouse society and its Chesapeake chapter, the Annapolis Maritime Museum, and Anne Arundel County.