Starting at the Sellicks Beach Ramp with large coastal cliffs behind your back, the route follows the entire South and Metro Adelaide coast heading North to Largs until the sand stops just prior to the North Haven Marina (and finishing at the playground in the Reserve on Lady Gowrie Drive) keeping to one simple principle - follow the coast and breaking water as closely as you can along the sand or rocks (not on esplanade pathways) except for getting on and off the Marion Coastal Trail and a short 500m detour around the Glenelg Marina. At the Onkaparinga River Mouth you can cross over and get your feet wet or scoot around on the path on the cliffs and over the wooden bridge past Southport SLSC.
This is a very unique trail running experience with not much elevation but constantly changing (and spectacular scenery), a fair bit of judgement to pick the best 'lines' through the mostly hard sand (with some soft patches here and there) and rocks and with less risk than many other more 'remote' FKT routes....possibly the longest beach FKT in the world (admins please correct if this claim isn't factual), and definitely in Australia at the time of publishing.
Credit and thanks also to Matt Angus and Ben Hockings for pioneering a similar route around 2015 (with a bit more leeway to include esplanade paths and detour around the section of coast in front of the old Pt Stanvac Oil Refinery). Our hope is that by setting up the FKT route here with the GPX file and principles above there will be a timeless and clear FKT challenge for many years to come.