The pond looked pristine, reflecting the wispy clouds and languid blue of a summertime Cape Cod sky.

The women gathered at its edge were not fooled.

They had scouted the pond months earlier and knew what was held in its depths: Hundreds of old beer cans and wine bottles, cracked golf balls and cinder blocks, wooden pallets and long-forgotten gewgaws.

The women had prepared for this moment. Trained for it. Passed a swim test. They set out into the water in life jackets and kayaks, snorkels and masks. Not one of them was a day younger than 65.

The trash never stood a chance.

Over the course of the next hour, the Old Ladies Against Underwater Garbage hauled as much trash out of Lovells Pond in Barnstable as time and space allowed. They filled the storage compartments of their kayaks with it, strapped it onto gear loops, balanced it across bows. A fishing pole. Part of a white plastic lounge chair. A wooden pallet. A disintegrating car tire. After ferrying it all back to land, the women marveled at the haul.

“You’re exhausted, you’re maybe a little sunburned, you’re filthy, and it’s the best feeling,” said Lisa Weiss, a retired high school math teacher and, at 65, the baby of the group.

The Old Ladies Against Underwater Garbage was started in 2018 by Susan Baur, now 86, a retired psychologist who lives in North Falmouth. She’d been salvaging random pieces of refuse while swimming the Cape’s ponds for years, and enlisting friends. The women formalized the effort and settled on a name. More women joined, a website was started, and entry requirements set: Members had to be at least 64 and able to swim half a mile in under 30 minutes and free dive to eight feet.

Word spread. A photo of them rescuing a toilet from a watery grave went viral, television crews trailed them, and, in 2024, The Drew Barrymore Show donated $10,000 to their cause (the group is a nonprofit, the women are volunteers, and Ms. Baur said there’s still $9,000 from that donation left). When the group’s size threatened to become ungainly, entry was capped. Today there are about 30 members and a wait-list. A few recent joiners admitted to begging their way in.

To date, the women estimate they’ve hauled 6,000 pounds of trash out of Cape Cod’s ponds.

“We are surrounded by so many really intractable problems, the water quality issues on Cape Cod are really serious, and the solutions have such a far horizon,” said Maggie Megaw, 72, who joined the group in 2022. “This is so tangible and immediate. We show up at the pond and swim, and we bring back a big pile of trash.”

The group cleans about 20 ponds a year, and, by now, have the operation down to a science. Each pond is surveyed for garbage in advance, and, before each dive, levels of harmful blue-green algae are tested. For the dive at Lovells Pond, the women were divided into three groups of divers and kayakers, while a beach boss wielding a clipboard, a checklist and a map oversaw logistics. The women wore swimsuits, water shoes, swim caps and wet suits and toted extra sunblock and hats. Shortly after noon, they set off into the pond.

Ms. Baur, in a snorkel and mask, began swimming slowly along the pond’s perimeter, about 30 feet offshore, face trained downward, trailing bubbles. Every now and then, she would flip underwater, butt up, and resurface with a piece of junk.

Over the next 40 minutes, the kayaks were steadily filled, with chunk of asphalt, a weighty rusty anchor, a slimy two-by-four, and lots of old beer cans and wine bottles.

“The drinking is getting obscene around here,” said Julia Benz, 69, one of the divers, after surfacing with yet another beer can.

Sometimes a muffled exclamation burbled up from a snorkel as wildlife came into view; a painted turtle, a family of sunfish, game fish with mouths torn by fishhooks.

Members say the group has reshaped their lives. They’ve grown stronger, because they’ve had to, in order to haul up heavy refuse from the bottom of ponds and onto kayaks. They’ve forged new friendships after relocating or retiring, after becoming widowed or divorced, after losing cancer-ridden breasts.

“I don’t quilt, I don’t crochet, that’s not how I’m going to fit in as I age,” Ms. Weiss said. “This feeds you in a different way.”

Robin Melavalin, 69, who’s climbed Mount Kilimanjaro twice, said that before joining the group, she’d been rather afraid of ponds and their murk. Putting on a mask and snorkel and diving for garbage changed all that. “There’s a whole underwater paradise in lakes and ponds,” Ms. Melavalin said.

Ms. Baur said that the husbands of at least two members had thanked her. Diving for trash offers great stress relief and tends to have a salubrious effect on the mood back home. “You don’t really want to live with unexploded ordinance, if you know what I meant,” Ms. Baur said.

And, as leader, she’s had to squelch her proclivity to get anxious and complain about physical discomforts, she said. “Now it’s like ‘suck it up, because they are watching,’” Ms. Baur said. “I’m going to show them that being old is OK.”

The dive at Lovells Pond was deemed especially successful. The women estimated the rescued trash weighed 1,000 pounds, their biggest haul yet. Carefully, with gloves, they began to transport it, piece by piece and trailerful by trailerful, up a sloped pathway to the nearby roadside to be hauled to a dump.

“The joy that we feel in bringing it out of the water and knowing it is no longer there, as I always say, the turtles and the fish, they’re all clapping, they’re all thrilled that this is no longer in their home,” said Diane Hammer, 70. “I mean, there’s no better feeling.”