Hundreds turned out on Thursday to ring in the New Year by

Hundreds turned out on Thursday to ring in the New Year by taking the Polar Plunge challenge by running into the chilly waters of Pontiac Bay, on the shores of Lake Washington.

Participants braved the cold, 47-degree waters up to at least their necks to earn the coveted badge of courage. For many the event is an annual ritual—a number of bathrobes and hats were adorned with badges from years past.

The event, which began in 2003, is on its 15th year. Initially attracting only a few hundred, it has quickly grown to become one of the larger polar plunge events in the city. Similar events were held on Alki Beach, Magnuson Park, and elsewhere.

View the full slideshow here.

Bracing for an icy impact, a man takes a dive into the waters.

Bracing for an icy impact, a man takes a dive into the waters.

We aren't exactly sure what it is, but it (they?) takes a menacing stroll through the water.

We aren’t exactly sure what it is, but it (they?) takes a menacing stroll through the water.

Fully dressed in business casual, a man celebrates his successful dip.

Fully dressed in business casual, a man celebrates his successful dip.

A man rushes to escape the cold water after taking a dunk.

A man rushes to escape the cold water after taking a dunk.

A woman carries her reluctant son out into the water for his dip.

A woman carries her reluctant son out into the water for his dip.

Hundreds turned out on Thursday to ring in the New Year by

A woman carries her reluctant son out into the water for his dip.

A woman bundles up in the arms of a friend before the plunge.

A woman bundles up in the arms of a friend before the plunge.

A participant heads back to shore after taking his dunk.

A participant heads back to shore after taking his dunk.

A woman surfaces after taking a dip.

A woman surfaces after taking a dip.

A woman takes a dive into the water.

A woman takes a dive into the water.

And then reacts to the chill.

And then reacts to the chill.

The crowd gets pumped before the plunge.

The crowd gets pumped before the plunge.

Having emerged from the water, a man dries off.

Having emerged from the water, a man dries off.

Thrashing about, a man ressurects himself from the water after taking a dunk.

Thrashing about, a man ressurects himself from the water after taking a dunk.

A brave soul tries to shake off the freezing water after taking her dip.

A brave soul tries to shake off the freezing water after taking her dip.

Soon to be plungers pose for photos in front of the official polar plunge sign at Matthews Beach in Notheast Seattle on January 1, 2015.

Soon to be plungers pose for photos in front of the official polar plunge sign at Matthews Beach in Notheast Seattle on January 1, 2015.

Plungers dry off after making the icy dip.

Plungers dry off after making the icy dip.

A couple exchange high-fives after taking the plunge.

A couple exchange high-fives after taking the plunge.

A young boy enjoys the cold waters of Lake Washington during the 2014 Polar Plunge.

A young boy enjoys the cold waters of Lake Washington during the 2014 Polar Plunge.

Seattle City lifeguards take a dive of their own after the crowds leave.

Seattle City lifeguards take a dive of their own after the crowds leave.

Dressed as Poseidon, a man weilds a trident as he walks slowly in over his head.

Dressed as Poseidon, a man weilds a trident as he walks slowly in over his head.

A late-coming group takes the plunge together

A late-coming group takes the plunge together

According to the board, the water temperature for the 2015 Polar Plunge was a balmy 47 degrees.

According to the board, the water temperature for the 2015 Polar Plunge was a balmy 47 degrees.

A woman gauges the temperature of the water ahead of the plunge.

A woman gauges the temperature of the water ahead of the plunge.

A man slips into the waters.

A man slips into the waters.

Two men test out the waters ahead of the main pack.

Two men test out the waters ahead of the main pack.

Donning fuzzy polar bear hats, a family is ready to make the dive.

Donning fuzzy polar bear hats, a family is ready to make the dive.

A cowboy hat showcases plunge patches from the past two years.

A cowboy hat showcases plunge patches from the past two years.

Small children wade into the chilly water.

Small children wade into the chilly water.

Dressed as Where's Waldo, a father and son duo make their way out of the water.

Dressed as Where’s Waldo, a father and son duo make their way out of the water.

Hundreds of plungers line the waters edge as the countdown begins.

Hundreds of plungers line the waters edge as the countdown begins.

Participans race into the water to take their dunk.

Participans race into the water to take their dunk.