Ravaged by stingers and battling nausea, Subiaco chiropractor Kirsty Sterle pressed on through the rolling swell.
The 26-year-old was most of the way to Rottnest and had more than 10,000 reasons to push through the pain.
Ms Sterle was motivated by the abused, abandoned and unwanted animals at the Dogs' Refuge Home in Shenton Park, where she volunteers once a week.
"I've raised more than $10,000 for the Dogs' Refuge Home so far for this year's swim," she said yesterday.
"I did the same thing last year but I didn't raise this much. I've been volunteering at Shenton Park for a couple of years now and I just wanted to do more for them.
"There are a lot of volunteers there who put in countless hours without much recognition. They save a lot of dogs from death row."
Ms Sterle's Rottnest swim time of six hours did not challenge any records, but it was a personal best and she earned the title of highest fundraiser - her contribution helping push the total to $106,000.
Clairly Lance has raised nearly $7000 for the McCusker Alzheimer's Research Foundation.
She trained for two years to be ready for the race so she could help fund research into the disease that affects her mother Molly.
Team Swim for Saba had four teams, a duo and a solo in the water in support of Saba Rose Button, a young girl with spastic quadriplegia who needs 24/7 care.
There were 65 people swimming for the ICEA Foundation's Waves program, including the event's first all-indigenous team.
In all, they collected $19,000 of a targeted $30,000 for the youth-driven reconciliation organisation.
The winner was former triathlete Paul Laver, 29, who added a solo victory to his wins in the duo and teams categories in 2010 and 2013 in a time of 4hr 14min. 4sec.
Mixed team Milly's Minions set a new benchmark of 4hr 9min. 24sec. and female duo Sacha (Jaime Bowling and Sacha Downing) completed the crossing in 4hr 22min. 46sec. Teenager Elizabeth Belliss, 19, won the women's solo swim in 4hr 52min. 32sec.