Hosted by the Mandurah Triathlon Club, this is a very popular event on the triathlon calendar.

Last year 180 competitors from throughout WA completed the 750m swim, 18km cycle and 5km run.

Another big field is expected this weekend.

Many triathletes regard the Interclub as their favourite event of the season.

It was initiated by Mandurah triathlete Clive Choate with the idea of promoting club spirit and friendly rivalry, as well as recognising Rob Pickard, the Triathlon WA president who, for almost a decade, had contributed so much to the sport.

Some of the Mandurah triathletes expected to do well include David Whiteley, Darryl Harris, Sandy Harvey and promising juniors Danielle Longworth, Gabi Miller and Nadia Atanasovski.

The cycle course has full road closure from 7.40am to 9.00am to maximise safety for competitors.

It goes from Doddi's beach along Halls Head Parade into Clipper Way, and then right into McLarty Road, right into Peelwood up to the roundabout at Casuarina Drive, before retracing the course back to Halls Head Reserve.

The riders will complete two laps of the cycle course.