Come Labor Day, a long melancholy creeps over the Jersey Shore.

"It's sort of depressing," Doug Maday remarked recently, and swept his arm at the vast, empty curve of sand where Seaside Park meets the sea.

Dusk was approaching.

"All summer there's so many interesting people on the beach," he said. "Then everybody leaves. Everything clears out."

It is a pattern that Maday, a used-car salesman who grew up in this Ocean County borough, and lives in nearby Island Heights, has seen play out for 49 summers.

But this year he got an idea. Call it crazy. Or not. Even he's not sure.

"It was the end of August," he explained. "I was in the ocean, thinking 'There's just a few more precious days before the end of summer, and I don't want it to stop.'

"And then I thought: 'Why should it? What if I did sort of an endless summer?' "

What would it be like, Maday wondered, if he swam in the ocean every day for a year?

He resolved to do it, and on Labor Day took the first of what promises to be 365 full-body plunges into anything the Atlantic Ocean throws at him.

"It's strange," the lifelong bachelor marveled on Thursday - Day 93 of a quest he likens to climbing Mount Everest. "I'm not a risk-taker. I'm not the kind of guy who says 'Hey, look at me.' "

He had arrived just before 4 p.m. at the shuttered lifeguard station at M Street and Atlantic Avenue wearing a gray hoodie, a black watchcap and green nylon track pants.

The dimming, hazy sky was pale gray on the horizon, and the great, sighing presence he half-jokingly refers to as "Mother Ocean" was in gentle state. Low waves were breaking about 60 feet out, arriving as soft rollers on shore.

Air temperature was 46 degrees, the water 49. This was the first day the water had dipped into the forties - 20 degrees colder than on Labor Day.

At 4:05 Maday approached the waterline, stripped to a knee-length nylon swimsuit, and strolled without hesitation about 15 feet in, up to his ribcage.

He dove under a roller, stood up when it passed, shook his head, and strolled back. Plunge 93 had lasted 45 seconds.

"That's it," he said, laughing, and reached for his towel. "That's the plunge."

It isn't, of course. Every plunge is different.

"My worst day was a nor'easter a couple of weeks ago," he recalled a short while later, over beers at the nearby Saw Mill tavern.

"The sand was whipping like 100 miles an hour, and the waves carried me south so fast it was like I was riding in a car." Two blocks later he made it to shore "with sand in my teeth."

He keeps a blog on his Facebook page which he updates each day with a photo and short account of his latest plunge.

"The weather was bad. Temps down. Rain falling," he wrote of his 5 a.m. swim on Nov. 6. "Not only that but I had a head cold coming on. Sickness. The cold sand, the cold air and dropping water temps work against me."

And yet some days are sublime.

"One day I was out there hearing church bells" from onshore, he recalled. "It was almost a religious experience. This beautiful thing. I was laughing out loud."

Another time, in mid-November, he was lying on his back "when these birds flew over," he said. "And they gave me this look that kind of said 'We don't see a lot of humans here this time of year.' It was weird."

He has thought of making the project into a fund-raiser for a charitable cause, but so far it's just been an existential thing. "There has to be a purpose to this, right?" he wrote in his Oct. 21 blog. "Well maybe, maybe not lol."

His 26-year-old nephew, Kevin Wingert, doesn't know what to make of his uncle's quixotic adventure.

"At times I'm supportive, at times I'm skeptical," but the blog is "really interesting," said Wingert, who studies entrepreneurship at Drexel University.

Despite his qualms, he believes his uncle should press on. "I'm thinking 'How much colder can it [the water] get?' Setting his health aside, he's got nothing to lose."

"He's doing something nobody else has done," said Andrew Mead, a friend of Wingert's who lives in Seaside Park. He watched Thursday's brief swim along with Jeff Potter, 59.

"There are some days he's crazy to go in," said Potter, who works for the Toms River school district. But he admires the fact that his longtime friend, whom he describes as a "quiet, unassuming guy," has "come out of his shell."

Most of Maday's plunges are solitary - there are no life guards - and four have been at night, which he calls "stupid" and hopes not to repeat.

Plenty more dangers await, however, in the 270 swims ahead.

Maday ticks off nor'easters, lightning, undertows, sharks, and hurricanes as possibilities - and water temperatures will be in the high 30s by late winter.

He is surprised at how comfortable the water feels even as it grows cold - and he refuses to wear a wetsuit because "that's cheating."

He might use a life jacket or a safety rope in life-threatening situations, but it's a "must" that his head go underwater each time.

"There's going to be times when I'm thinking 'This could get dangerous," Maday concedes, "but I'm not going to stop. I'm just not.

"It's not a comfortable thought," he said. "It's going to be very, very hard."