In Southie, they came, they thaw, they shivered

Don't tell Jeb Banks it's easy to jump in the Atlantic Ocean in January just because the sun is out and the thermometer reads 50 degrees. Banks and other members of the L Street Brownies, who participated in the group's 101st consecutive New Year's dip yesterday, prefer colder days, when the air temperature matches the nerve-numbing 36-degree water.

"It's easier when it's 30 degrees. It's less of a shock when you hit the water," explained Banks, who made his sixth New Year's dip yesterday in a festive red-white-and-blue felt hat.

The balmy weather drew a record 600 registered swimmers and an additional 2,000 spectators who lined the beach behind L Street Bathhouse in South Boston for the granddaddy of New Year's swimming events. Perhaps 100 other groups take a New Year's Day plunge in cold-weather regions, but the Brownies boast that they were the first and probably one of the fastest growing, as entire families make it a New Year's tradition.

"Everything else is all downhill from here," said Barry Jennings of Dorchester, joking. He jumped into the water with his son, Conor, 13, and daughter, Victoria, 9.

Temperatures in the city yesterday reached a high of 52 degrees, said Charlie Foley, a meteorologist at the National Weather Service in Taunton. Over the past 30 years on Jan. 1, the temperature in Boston has averaged 38 degrees, Foley said. The city's record high for the date was set in 1876, at 70 degrees, and the record low was minus 3 in 1918.

Though far from a record high, yesterday's temperatures made for a memorable backdrop at the L Street event.

To the strains of the "Marine Hymn" played on bagpipes by the Boston Gaelic Fire Brigade, the swimmers marched out of the bathhouse about noon, huddling on the sand inside police barricades as spectators roared their approval and took pictures. Then they began a slow-motion stampede to the water as wave after wave of swimmers got their turn in the Atlantic.

Most swimmers didn't go more than 50 feet into the water and stayed just a few minutes, some seemingly more concerned with fashion than swimming. Three were dressed as Christmas stockings marked "Red Sox," while another wore a full Santa suit, and many sported weird hats or waved an Irish flag. David Folkerts carried a female mannequin in bikini and beads. "I think once we get in the water, she'll be all right. This is her first time," he explained.

Then there was Tom McAuliffe, who repeatedly played the cavalry charge on his English horn and stayed in the water for 30 minutes, mugging for photographers. "I'm down here swimming every day," said McAuliffe.

One Brownie who couldn't make the swim this year was John Langton Jr., who is serving in the Army's 96th Division in Qut, Iraq, south of Baghdad. But about 20 family members and friends, including his brother Brian, took the swim on his behalf, while sister-in-law Lorrie Langton took pictures. She planned to e-mail them to the soldier, who planned to ask his superiors for permission to jump in the Tigris River to keep his 20-year New Year's swimming streak alive.

Swim organizers could not have been happier with yesterday's event, which nearly doubled the number of participants in 2003, when there were 360 swimmers. A few people reported temporarily numb extremities after the ocean plunge yesterday, but they warmed up quickly when they left the water. "Things went off without a hitch," said L Street organizer Freddy Ahern.

Scott Allen can be reached at allen@globe.com.