Around 135 swimmers braved Sunday's cold and dived into The Breakwater for Let's Talk's Lady Bay Laps.
The swim-a-thon saw teams challenge themselves to as many 500 metre or one kilometre ocean swims as possible for four hours.
Let's Talk foundation coordinator Jacinta Roache said the event was a success.
"We are here to change the stigma around mental health and to get healthy and active," she said.
"We aim to engage the community in a range of sporting activities throughout the year to promote healthy lifestyles.
"This leads to creating choices to help with mental health."
In its first year, the Lady Bay Laps had 29 teams enter with some participants swimming up to five laps solely.
One team called Me, Myself and I comprised of John Sheely whose non-stop approach to the event saw him swim a massive 12.5 kilometres.
The Killers took out the total distance covered by a team with 17 kilometres.
Ms Roache hopes Lady Bay Laps will be back for many years to come.
"Swimming, as well as cycling, are fantastic sports for mental health and well being," she said.
"We're absolutely stoked with how the event turned out.
"There were no incidents and lots of conversations started.
"It was a great way to introduce more of the community to what the foundation is doing so they can become ambassadors themselves."
Head to letstalkaustralia.org to find out more about the foundation and to get involved in their upcoming events.
Have you signed up to The Standard's daily newsletter and breaking news emails? You can register below and make sure you are up to date with everything that's happening in the south-west.