In what has become a New Year's Day tradition in Onset, hundreds of people sprinted into--and then quickly out of--the icy waters of Onset Bay for the 10th annual Onset Box 5 Association Polar Bear Dive.

Hundreds of onlookers gathered on the beach and the pier, clutching hot cups of coffee in one hand and smartphones in the other to document the friends, family members and flat-out crazies taking the polar plunge.

"My fingers are already numb!" said Michelle Montrand, about a half hour before the dive.

This was the fifth year in a row that Montrand, a second grade teacher at Decas Elementary School, has jumped into the Bay on New Year's Day.

She said she challenged herself to do it five years in a row but will probably do it for another two years so she can say she has done it at 60 years old.

"It's for a good cause and a nice way to start the new year," she said.

The Box 5 Association uses the proceeds from the Polar Bear Dive to fund scholarships, fill food baskets for the needy during the holidays, and support other charitable causes. Two years ago the group raised nearly $5,000 when 274 took the polar plunge.

Some people wore t-shirts, some were in speedos, and some were even dressed as superheroes.

Tammie Glass from Hanson, was dressed as Wonder Woman and jumped in the water for the third year in a row. She was accompanied by her friends, Laura and Lain Potter as well as Apryl Rossi of Wareham, who was jumping in for her first time.

"It's a bucket list thing for me, to do something that is completely insane." said Rossi.

Coming out of the water, Rossi was speechless, while Laura Potter said, "it was colder than last year."

The temperature of the water, hovering around 40 degrees, was compounded by the harsh wind. The temperature at noon was 31 degrees.

Montrand said there have been years when people have trudged through snow to get in the water, but she thinks this year was the coldest thanks to the wind.

After the frigid frolicking was done, everyone was all smiles as they dried off and put on warm clothes.

"It's a way to start the new year off with some fun," said Erin King, who was coaxed into jumping in the water this year by her friend, Cheryl Bushnell.

They both plan on coming back next year.

"It was fantastic," Bushnell said "We're going to make it a tradition."