Four years ago a Damariscotta nurseryman thought it would be cool to start a regatta of giant pumpkins, hollowed out and afloat, if not altogether seaworthy.

Still, to venture forth on Columbus Day in a pumpkin that once weighed more than 1,000 pounds is proof of something. Nobody is quite sure what, but the idea of racing pumpkins boats has taken root.

Buzz Pinkham grows enormous pumpkins with natural fertilizer at his Pinkham’s Plantation in Damariscotta. It’s not really a cash crop, just fun.

At the first regatta there was one giant pumpkin, the second year, two. This Columbus Day, pumpkin seafarers piloted 14 orange or white coracles, using oars, paddles, low-horsepower outboard motors and in a class by itself, a shipshape sloop rig.

Dana Everett of Bremen used a variety of household items including a towel-rack traveler and shovel-handle tiller. His brown sails, made from pure plastic tarp, were rigged with the finest clothesline.

But, as these uncommon boats went round and round-something they do very handily-it was apparent to the hundreds of enthusiastic onlookers that winning was only one aspect of yachting in a squash. Staying afloat is another, laughing and yelling and decorating your vessel is also part of the experience.

A Searsport mariner, Kristin Cameron, wrote in an e-mail after the event expressing gratitude to the organizers and “to the people who stood in the water for a long time to help out, and to the rescue boat that I unfortunately required. The big green Dragon Pumpkin Machine served us well. I’ve never had so much fun with or inside a veggie before,” she said.

A local woman, Whitney Rice, won a pumpkin-paddling race in Flower Power, her victory coinciding with her 18th birthday.

The Great Pumpkin Regatta brought lots of people to town, and that fact wasn’t lost on local merchants who reported brisk sales. Main Street was lined with great pumpkins turned into things like a giant spider or jack-o-lantern style carving, a massive job with a very plump squash of gigantic girth.

You start a giant pumpkin from seed in early spring, and set it out by May. In less than two weeks it can grow to 30 inches in diameter, and in a month can weigh 450 pounds, Pinkham said. He has seen a pumpkin gain 35 pounds in a day, he said, which sounds a lot more exciting than watching grass grow or paint peel.

Pumpkin boats have a lot to recommend them, although their builders don’t advise that you eat them. You can recycle most of the material simply by dumping it on your compost heap, and indirectly, this year’s boat might become part of next year’s bigger boat.

If the current trend continues, the Columbus Day Great Pumpkin Regatta could grow and grow until it’s…enormous.