Olympic swimmer Jarrod Poort will be setting the pace for the hundreds of freestylers diving in to help raise money for people living with multiple sclerosis.
Keeping up with the 1500-metre specialist is a mega task in anyone's book, but swimmers don't be discouraged.
Backstroke, doggy paddle and dolphin kick are all acceptable styles in the MS 24-hour Mega Swim.
It's all about how many metres you complete, not how you get there.
Last year more than 225 swimmers from 17 teams swam more than 1000 kilometres and this year event organisers are hoping to attract more swimmers for the March 2-3 event at the University of Wollongong's Recreation and Aquatic Centre.
Money raised goes to the Go for Gold Scholarship Program, which helps people living with MS "aspire to their best and live out a life-long dream".
Clinical dietitian Anita Graham, co-ordinator and driving force behind the swim, said she had a close family member with MS and saw the effect it can have on their lives and their family.
"I also have a zeal for sharing my love of swimming. I grew up in the sport and competed at high levels, so bringing the two together in this way has been very rewarding," she said.
Mega Swim committee chairman Peter Brown said swimmers of all ages and abilities loved taking part.
"It's become an increasingly popular fund-raiser for Figtree Lions Club and MS Australia," he said.
Figtree Lions Club members will keep dry, but work shifts throughout the 24-hour period making sure swimmers are fuelled with snags, steaks, eggs and bacon, all the while logging laps for participants.
Register a Mega Swim team at megaswim.com.