The Taieri Mouth Multisport and Duathlon will be held from Knarston Park on Sunday.
The multisport event includes a 6km kayak in the lower Taieri Gorge, an 11km run along the Millennium Track, and a 28km mountain bike ride, or 35km road- cycling ride to Brighton and back.
Participants can drop the kayak and stick to the biking and running.
"Some people don’t like to paddle so we’re doing a duathlon," event organiser Scott Weatherall said.
Those participants will get a ride up the river in a boat and join the multisport athletes as they are heading off on their run.
This is the first year a road-cycling option has been available.
The aim was to make the event accessible to as many people as possible, especially those who might have been deterred by the mountain biking.
"We know that a lot of people enjoy the area, so it was just about offering that as an alternative option."
Making the distances achievable was important to encourage people would "give multisport a crack".
The event doubled as the Dunedin Tri Club’s multisport championship for club members.
Activities for children will be available on the day, including beach runs and sandcastle-building, but it was not a babysitting service.
"Family is a big part of multisport."
Amadeo Enriquez-Ballestero will also be performing some science experiments.
Weatherall was looking forward to the event and showing off Taieri Mouth’s beautiful scenery.
"It’s just a wicked part of the country."