Author, historian, yachtsman, crew oarsman, coxswain, and coach, and retired teacher Roger F. Duncan may move slowly and wear a hearing aid, but his mind remains swift and clear as does his wry, impish sense of humor. In response to a, “Good for you!” at hearing he’d reached 92, he replied, “I’m not so sure.”

Although better known to the public for his Coastal Maine: A Maritime History, many editions of A Cruising Guide to the New England Coast (with John P. Ware), and four other books mostly on sailing, at the advanced age of 80 Duncan began researching his first work of fiction: The Reluctant Patriot, published in 2006, a historical novel based on this country’s first naval engagement, the Battle of Machias. The idea came to him, he said, while studying the history of the Maine coast when he came across the wreck of a British naval schooner, Halifax, which went aground by striking a rock off what is now called Halifax Island at the mouth of Machias Bay in February 1775.

Despite researching all kinds of documents on the vessel, crew list, and court-martial proceedings, Duncan could not find the name of the ship’s pilot, who had been found to blame in the court proceedings, but never named. So Duncan decided to invent him and came up with a reasonable story of how the ship inadvertently struck the rock hidden by a higher-than-usual “moon” tide, a perfect tale for a historian who loved to sail and loved researching the ins and outs of the Maine coast.

Duncan and his wife Mary, who refers to herself as his first mate, both then octogenarians, took their Friendship sloop, Eastward, to Halifax Island where Roger went ashore to study where and how the wreck could have happened, leaving Mary, nursing a bad knee that left her unable to clamber over rocks, on board to worry how she’d manage if her husband broke a leg while on the island. Nothing untoward occurred, and Mary Duncan judged it, “Altogether a good trip.”

It was one of many such made by Duncan and his family who started coming to Maine in 1925. His parents rented a house in New Harbor and only left, years later, because the owners sold the house. One of Roger and Mary’s three sons did the architectural design of the East Boothbay house they have lived in since 1970.

Asked what he considers the biggest change to the coast since he started coming here, Roger replied, “More people, more boats, more cars, more gift shops.” Mary chimed in saying, “There are practically no more little grocery stores on the shore. You have to go to the supermarket.”

Roger graduated from Exeter followed by Harvard University in 1938, having been coxswain for crew practice boats at both school and university. He taught primary education at the Fenn School, in Concord, Mass., from 1938 to 1945 when he moved on to Belmont Hill, in Belmont, Mass,, because he wanted to teach and coach older boys. He and Mary, whom he married in 1940, stayed at Belmont until his retirement, in 1981.

Besides coaching Belmont’s crew team, Roger taught English mostly, and some history and Latin, and said, “I never got into French,” explaining, “my accent is, shall we say, suburban.” Attesting to her husband’s popularity with his students, Mary Duncan said of his former students, “They keep coming down the driveway here.”

As for their summers, the Duncans began by getting the boat ready each spring so it could go in the water by July Fourth, then sailing with and without passengers almost every morning and afternoon until Labor Day. Fitted with four bunks, Eastward was licensed for six passengers.

Asked what aspect of his life he liked best, Roger answered with a rhetorical, “Which leg of the chair is best?” He then went on to say that although he liked writing and reading, “Teaching was the central interest,” adding, “our boys were important, and rowing is.”

Mary continued, “After September we’d go bursting into Belmont. In spring, crew was everything. Crew, then up here [Maine] to get the boat in the water.” They followed this schedule for over 40 years.

Roger loved coaching crew and said, “I had a single shell and raced on the Charles [River] for years. Mary said, “Roger got a medal for the fastest one over 70,” adding that he has a box of medals.

And don’t think this 92-year-old retiree just sits around reading and taking naps. Try to make an appointment with him, and you’ll see. He goes from dinner guests to a speaking engagement to more people dropping by to see him. On and on it goes: appointments, guests, meetings, and talks, with naps in between, day after day. Mary makes and keeps the schedule and does her best to care for them both. It’s harder than anyone who hasn’t reached their ages can imagine.

Taking on such a project as a historical novel based on a factual incident on the Maine coast during the American Revolution would be beyond most octogenarians. For Roger Duncan, though, with his background and local knowledge, it had to have been as natural as drawing breath.