The annual event sees competitors from across the nation do battle in a series of running, swimming and biking events along and around the Esplanade Green, Coles Bay.

The main event - the Knight Frank Coles Bay Half - will see national, state and local entrants tackle a 1.9km swim on Muirs Beach, followed by a 90km cycle on Coles Bay Rd, before a 21.1km run along the Esplanade and Muirs Beach.

The Half can be tackled either individually or as a team of two or three.

Coles Bay Half committee member Mark Padgett said this year's event was an expansion on previous years.

"Our committee has spent the year competing in and visiting various other events to gain valuable experience and knowledge and we came back with a purpose - to expand our triathlon to provide a range of activities to appeal to everybody's fitness and age level," he said.

Mr Padgett said this year's event had been bolstered by the addiction of new attractions tailored to different age groups.

A new addition in 2015 is the Tasnetworks Coles Bay Kids Challenge, featuring child athletes aged from seven to 13 in a swim and run event at Muirs Beach.

"Children will embark on this challenge in the afternoon once most of the big kids have finished the Half, so they are able to cheer on the kids. Once completed the swim and beach run, the children will be joining the senior competitors along the finishing shoot to receive their medal."

All the action will get under way from 10am.