Two to three times a week, year-round, Richard Carney of Brunswick spends hours with his entire arm stretched into the mud of lake, river or ocean waters. If he feels a bottle or something else, he brings it up. Sometimes, it can be quite a find, like an unusual whole piece of crockery or an undamaged 1700s bottle. Sometimes, he finds just the one piece; other times, there is a pile of the same sort of artifact, like the numerous clay pipes he found recently in New Hampshire waters.

Each dive is a new adventure. A man of great enthusiasm, he admits that occasionally, when he comes up with a special artifact or locates a rich site, he will “get giggly underwater” and yell, “All Right!”

Now 46, Carney has been diving for about 25 years, bringing home 2,000 to 5,000 items a year. He has kept some, sold many and turned others into crafts. Two years ago, he added a sideline when he decided to do something with the mounds of sea glass he was pushing aside to reach the bottles and other artifacts. “I had an epiphany,” he says. “Sell it.”

He started to bring home bags of the sea glass, which, he explains, is generally larger than the pieces beachcombers find because it hasn’t been tossed by waves. He takes bags of the glass to Bea Furbish of Brunswick, and she picks assortments to fill old-fashioned Bell Mason jars. Carney sells between 100 and 200 of the jars a year at antique and gift shops along the coast under the name Old Bottle Sea Glass of Maine. He also sells in bulk to craftspeople.

Carney began collecting bottles when he was a kid living in Buxton and in Winthrop, where he was close to a 1770s stagecoach inn. He picked through land dumps of the inn and existing and defunct old farms. But those sources were scoured, he says, during the “seventies bottle craze,” and good finds became scarce.

He joined the marines at age 18, and when he got out, decided to take a different approach to finding artifacts: locate underwater sources and dive. He finds his sites in many ways, often using old maps and local lore. For an upcoming dive, he had consulted an 1877 map of the South End of the City of Bath and Winnegance. Unrolling the map, he points to an area just beyond the causeway, where he says he’s counted 49 houses perched above Winnegance Lake. Knowing from experience that residents living by the water in the 1800s often chucked what they didn’t want out the windows on the water side, he figures the site is full of artifacts.

Other favorite sites are off old docks, like the town dock in Wiscasset. That location is loaded with wine and spirit bottles, the trash, he believes, from several 19th century taverns in the town. It’s one of his prime sources for sea glass. Another rich location is the site of an old stone pier across from Center Pond in Phippsburg. Picking up a bottle he found there, he shows that a name is visible: Hartlib & Shelter Soda Co., which he says was in Bath during the 1890s.

Often, Carney will know a dumping ground must exist for an old luxury hotel, but he isn’t sure where. To locate the dump for the Kineo Hotel on Moosehead Lake, he says he traveled to Rockwood and asked around for the oldest person in town. That turned out to be a fellow named Buster, who told him trash used to be hauled from the hotel and left on the ice between Moody Island and Kineo. When the ice melted, the trash went down. Carney explored the underwater site and found a huge hump that was filled with all sorts of bottles and crockery.

When faced with a general area, Carney locates an exact site by using what he and his friends acknowledge is his special power of intuition. “I have the gift,” he says. “I’ve had it since I was a boy, when I could look at a property and immediately say, ‘The dump is over there.’ ” He has used this intuitive power to help people, such as an 89-year-old woman who couldn’t find $270 and wedding rings belonging to her and her deceased husband. She had put them in her secret hiding spot, and they were gone. She was convinced someone had stolen them. “I went there and dowsed the house and then sat down on the living room floor and told her to look in the lower left hand corner of a rolltop desk,” he says. “The rings and money were there under a piece of rug.”

Carney’s diving experience hasn’t been without perils. He has dealt with boat traffic, murky waters and algae blooms in summer, and once was attacked by a snapping turtle he surprised when he swam around an underwater hill in Bryant Pond, Maine. Another time, in Bethel, a school of horned pout swarmed around him. They wanted to go into the hole he was making in the mud while he extracted coins and jewelry from a site where a swimming beach had been located. He often dives alone, but never goes under ice or in the treacherous tidal waters at the mouth of rivers like the Kennebec or Piscataqua.

Over the years he has packed bottles into numerous boxes that line his garage and the workroom where he repairs copy machines (his other business, Excel Copier Service). Some bottles are whole and can be sold; Carney may use the broken ones to make lampshades or sea glass windows. He has found these and other artifacts during dives in Maine and New Hampshire rivers, in lakes, off the coast of islands and other ocean sites and as far away as the Delaware and Charles Rivers.

Carney is especially interested in artifacts from 1790 to 1860. He keeps many of his best pieces and augments the collection with items he buys. There are bottles of all types: flasks, medicinal bottles, pickle, ale and wine bottles. One of his prize discoveries is a whole 1804 U.S. Navy mustard bottle made of flint glass; another, a 1760s wine bottle found in the Sheepscot River. He found an 1870s spittoon in the Connecticut River. “I saw the top of it and thought it was a hubcap,” he says. “But then I fanned away the sand, and this whole thing emerged.”

When he packs his van for a day’s dive, he can’t be sure what he’ll be bringing home. “It’s always like a treasure hunt,” he says. “You never know what you’ll find until you go out and look.”