Local author Harry Gratwick will share tales from his sixth book about Maine, “Historic Shipwrecks of Penobscot Bay,” Thursday, July 17, at 6 p.m. in the Friends Community Room of Rockland Public Library, 80 Union St.

Thousands flock to the beautiful coastline along Penobscot Bay every year, but the dark sea has often turned treacherous. Craggy rocks can be virtually invisible to oncoming vessels such as the Alice E. Clark, which simply strayed off course in good weather. Other ships, such as the Governor Bodwell and Royal Tar, were destroyed by fire. But not all of the ships were a total loss — some were repaired and resumed life under different names. Gratwick will explore some of Penobscot Bay’s most historic and dramatic shipwrecks, from what caused them to what happened during those fateful moments when the ships were going down.

Gratwick is a lifelong summer resident of Vinalhaven and a retired history teacher who had a 46-year career as a secondary school teacher, coach and administrator. He spent most of these years at Germantown Friends School in Philadelphia, Pennsylvania, where he chaired the history department and coached the baseball team.

Gratwick is an active member of the Vinalhaven Historical Society and has written extensively on maritime history for two Island Institute publications, the Working Waterfront and the Island Journal. Books will be available for purchase and signing.

This is one in a continuing Thursday series of literary, film and cultural offerings sponsored by the library and Friends of the Rockland Public Library. Admission is free. Special accommodations for persons with disabilities can be made with 48 hours notice by calling 594-0310.

Courier Publications’ A&E Editor Dagney C. Ernest can be reached at (207) 594-4401 or dernest@courierpublicationsllc.com.