The Port to Pub Marathon Swim is a 19.7km or 25km ultramarathon channel swim from North Fremantle to Rottnest Island, Western Australia.

It is one of the longest open water swims in Australia and the Southern Hemisphere, taking place annually in March.

Swimmers participating in the 25km ultramarathon channel swim will complete a 5km loop parallel to Fremantle Beach before crossing the channel to Rottnest Island.

The Port to Pub Marathon Swim is one leg of the Marathon Swimming Foundation’s (MSF) Australian Triple Crown of Marathon Swimming challenges.

Swimmers can either choose to complete the Port to Pub Marathon Swim individually, in a duo or teams of four.