See the fastest route for the Rottnest swim

See the fastest route for the Rottnest swim

Making her first attempt at a solo Rottnest swim this year, Ann Perkins is hoping science can help ease some of the pain of the gruelling 19.7km crossing.

Ms Perkins is a former student at the University of WA’s Oceans Institute and dropped in on her old professor Chari Pattiaratchi yesterday to find out how to make best use of the currents in order to reach the island with the least amount of effort.
Professor Pattiaratchi has developed a simple program that all Rottnest swimmers can access which shows that the shortest route is not always the quickest or easiest.
This year, north-easterly winds and lack of a sea breeze later in the day means the currents are likely to be flowing from north to south and will increase in strength during the day, particularly as swimmers get closer to the island.
Professor Pattiaratchi’s program predicts that rather than trying to swim in a straight line, they should head northwards in a slight arc, enabling them to then drift back towards the island with the strengthening current as they near the finish line.
He said those who try to take the shortest route were likely to end up being pushed south of the island and would have to swim into the current to reach the finish, making the trip considerably harder. 
“This will help people to get there with less effort and to also help the boats to navigate the swimmers in the right direction,” Professor Pattiaratchi said.
Swimmers can get access to the program at rs-data3-mel.csiro.au/rottnest-swim-live/. They then need to click on the Cottesloe locator icon and enter their start time and estimated overall time. The course heading (shown as degrees) also needs to be adjusted to the north.
If they result does not show them hitting the island, they need to readjust their initial course.


See the fastest route for the Rottnest swim - Grant Taylor, The West Australian, 24 February 2017