Some 1500 people braved the 3C air temperature to strip off at 7.42am on Tuesday and mark the shortest day of the year.

The water was a comparatively warm 12C.

"This is the first time we've done it," Brady, 31, who hails from Brisbane, said.

"It was great to see how many people there were. When you get in, you just run in screaming. You can't really feel it until it's too late.

"The skin starts to sting. (And) it does shrink."

About 2000 people took the plunge in 2019 but the 2021 version was capped at a lower level due to COVID-19 protocols.

Tickets for the free swim, which signals the end of arts and food festival Dark Mofo and is considered an act of purification, were snapped up in a matter of minutes.

The dip began in 2013 with about 230 participants but has grown considerably in popularity since.

Red smoke and shrieks filled the air at dawn after tribal drums provided the countdown for towels to fall to the sand.

"We were here and I thought it's probably a thing we'd never do again. No regrets," Sangitha, 28, said.

Dark Mofo was called off in 2020 due to the pandemic and has run over a shorter period this year.

The future of the event appears under a cloud, with creative director Leigh Carmichael signalling it may have run its course.

Australian Associated Press