We New Englanders think we know lighthouses. Images of iconic coastal beacons are everywhere, from stirring (if hyperbolic) motivational posters, to sunset photos on Facebook, to the Cape Cod Potato Chips logo. We see them on sailing trips, or days at the beach, or long drives along the coast.

But recent events are shining a new light on these seaside sentinels, only two-thirds of which still function as navigational aids. Some lighthouses are passing into private hands. Some have become offshore inns for short-term swashbucklers. More ominously, even celebrated landmarks are being threatened by storms related to climate change, and could be at risk of destruction after centuries of guiding sailors to safety.

Yet lighthouses continue to inspire photographers, poets, and history buffs; this spring two new books about lighthouses have been released. As the ­area gears up for the 300th anniversary in September of Boston Light, the country’s oldest lighthouse station in the Boston Harbor Islands National and State Park, one writer — lighthouse historian Jeremy D’Entremont — cautions that a number of the estimated 800 lighthouses remaining in the country (of about 1,000 original lighthouse stations) are in dire need of upkeep.

In particular, he points to aging offshore lighthouses, those stalwart towers perched on rocky ledges or small islands, posing logistical challenges for even the most devoted preservationists.

“One of the hardest things is getting people to realize that lighthouses need help and money,’’ said D’Entremont, the New Hampshire-based author of more than a dozen books on lighthouses and maritime history, including “Boston Light: Three Centuries of History.’’ “People don’t realize the federal government is no longer taking care of all these structures. It’s falling to nonprofits, where the lack of money is a constant struggle.’’

If lighthouses are endangered, however, it’s not for lack of love. The Facebook page for Friends of New England Lighthouses, launched by D’Entremont, now has more than 9,600 members who actively post photos and reflections.

This spring saw the publication of the 500-plus-page “Brilliant Beacons: A History of the American Lighthouse’’ by Marblehead resident Eric Jay Dolin. Dolin delves deeply into the technological evolution of these navigational lifesavers and the lives of the men and women who kept them lit through time and tempests.

They have much to teach.

“Lighthouses created a wonderful backbone of a book [to explore] all kinds of threads of the American experience,’’ Dolin said. “They reflect the growth of the nation, tragedy, personal inspiration, architecture, engineering feats, heroic rescues, devastating storms, maritime commerce, and industrial and scientific design.’’ They were essential to the commercial progress and military strategies of the American colonies. And they were often targets in wartime.

Take Boston Light, the country’s first lighthouse, built in 1716 on Little Brewster Island, which will be feted summer and fall with a host of activities. It’s widely known that the British blew up the original Boston Light with a keg of gunpowder when they evacuated Boston in 1776. However, the British were only returning the favor to patriots who had twice before attacked Boston Light and put it out of commission, actions Dolin details with great relish.

“Look at it this way: Lighthouses don’t distinguish between friend or foe. They help out anybody,’’ Dolin said. “So they can help the home team or they could help the enemy.’’

Thanks to the Brits, New Jersey can boast of having the nation’s oldest continuously operating lighthouse, Sandy Hook Light, completed in 1764. But perhaps America’s most popular lighthouse is the Portland Head Lighthouse in Cape Elizabeth, Maine, said Dolin: It gets more than a million visitors a year.

Many mainland lighthouses, like Portland Head, are well preserved. But others are vulnerable to tides and fierce weather. In 2005, Hurricane Katrina swept away Chandeleur Light off the coast of Louisiana, which dated to 1848. Old Orchard Shoal Light in lower New York Bay, built in 1893, was destroyed by Superstorm Sandy in 2012. “After the storm, there was nothing there,’’ D’Entremont said.

And last year, the 160-year-old Gay Head Light on Cape Cod was moved 129 feet to protect it from an eroding shoreline.

Under the National Historic Lighthouse Preservation Act of 2000, federally owned historic lighthouses determined to be surplus may be transferred at no cost to local governments or nonprofit and community groups. That is how the American Lighthouse Foundation, founded in 1994, came to own two of the 18 lighthouses it oversees. Duxbury Pier Lighthouse is currently up for transfer.

If a suitable owner is not found, surplus lighthouses are auctioned by the US General Services Administration. Each year, a few go up for sale, with prices varying from “$30,000 to just shy of a million,’’ D’Entremont said.

Through this process, Boston-area special effects expert Dave Waller and his wife, Lynn, bought the remote and spectacular 113-foot Graves Light in Boston Harbor in 2013. The wave-swept granite tower of Minot’s Ledge Light, offshore from Cohasset, was purchased at auction in 2014 by Polaroid chairman and philanthropist Robert “Bobby’’ Sager. (If you’re hankering for your own beacon, see what’s available at: www.nps.gov/maritime/nhlpa/noa.htm.)

Living in a lighthouse was a childhood dream of Nick Korstad of Fall River. “When I was a little kid I wanted to be a lighthouse keeper; when I got older, I realized there were no more lighthouse keepers,’’ he said.

Korstad realized his dream in 2010 when he bought the surplus Borden Flats Light in Fall River. He has turned the 1881 lighthouse into a guesthouse where paying customers can be “keepers’’ for a night or two. It’s still a working lighthouse — the US Coast Guard maintains the light — but Korstad is responsible for the upkeep of the rest of the property, which, he acknowledges, is “challenging.’’

Nonetheless, the 35-year-old just obtained another lighthouse. He’s created a lighthouse preservation nonprofit that was recently awarded ownership of the Stratford Shoal lighthouse in Connecticut. He plans to restore it and run lighthouse keeper educational programs.

While private ownership of national treasures may give some lighthouse purists pause, Dolin concludes that nonprofits and governments can’t care for all the nation’s aging lighthouses, and the private sector has proven to be a bulwark against further demise.

Korstad does express concern about the future of lighthouses, noting that many of today’s lighthouse tourists are in their 50s or older. “If the millennials don’t take an active interest, the organizers of nonprofits [preserving lighthouses] will pass away and no one will take them over,’’ he said.

For the moment, “lighthouse tourism is very strong,’’ Dolin said. “Lighthouses conjure up in your mind a vision of the past. They allow your imagination to wander: What would it be like to be a lighthouse keeper? What if I were a mariner out at sea coming to the United States for the first time and finally see a light that indicated I was close to port and safety?’’

Tours, visits, more

For Boston Light events:www.bostonlight300.us

To visit Boston Light:www.bostonharborislands.org/#!boston-light-tours/c1dhs Tours run June 17-Oct. 2

To stay overnight in a lighthouse:www.bordenflats.com/ and

www.roseislandlighthouse.org/keeper_options.html

For minivan lighthouse tours by Jeremy D’Entremont www.newenglandlighthouses.net/new-england-lighthouse-tours.html

Stephanie Schorow

Stephanie Schorow can be reached at sschorow@ comcast.net