There are 32 entries across the grades and the inclusion of Asian Games gold medal winner Keisuke Ushiro of Japan, who has an impressive 8308 points to his name, and countryman Yuta Notoyo add an international flavour to the men's decathlon.
This will provide Brent Newdick, 12th at the London Olympics, the competition to regain a slot in the team for Rio.
New Zealand University representative Jack Henry was in sparkling form at the Porritt Classic last week and last year's Junior Champion and former Wanganui Collegiate athlete Max Attwell has his first senior decathlon.
In the women's event is Portia Bing, who represented New Zealand at last year's World Championships and in her debut finished a creditable 16th.
Her personal best score is 6102.
Bing's main competition is fellow Olympic berth seeker Veronica Torr, originally from Palmerston North.
Torr is the defending champion and set a personal best of 6051 points in Brisbane in January.
Both are close to the 6200 qualifying standard and Whanganui sport and the atmosphere provided could secure them as Olympians.
-The action starts at 11am on Saturday and will conclude around 4pm Sunday.