"It's hard to say where I'll finish because I don't know who is in the field, but I will try and get top five."
The Lake City Athletic Club member has a strong background in running but will rely on his road cycling ability tomorrow, after spending plenty of time on the bike.
"Running is normally my strength but I have had a calf and Achilles injury," he said.
Teams or individuals will face a 1.9km swim, a 90km bike and a 21km run tomorrow. A quarter ironman is also on offer.
Rotorua Half Ironman race director Shane Hooks said entries were up about 100 entries on last year.
"It's fantastic," he said.
"People come to this race because they want an honest challenge."
He said Lake Tikitapu (Blue Lake) was also one of the best lakes in the country to race in.
"It has got the best swim of any triathlon in New Zealand. We have never had a rough swim and the water is going to be close to 20C tomorrow."
Hooks said the toughest part of the race would be biking up Tarawera Rd, towards Blue Lake, and the climb between Blue and Green lakes during the run.
"But that is what people are coming here for. They love that," he said. "They won't love it at the time but they will love it afterwards."
The winners of the Rotorua Half Ironman receive a giant fluffy teddy to take home, as part of the event's tradition.
Professional triathlete Oliver Shaw, from Rotorua, will race in the Taupo Half Ironman tomorrow after finishing second at the Rotorua Half Ironman last year.
The Taupo Half Ironman offers prize money and has attracted 18 professional men and eight professional women.
The Taupo event is also a TriNZ sanctioned event which means competitors can earn qualification to the Half Ironman Word Championships in Canada next year.
Organisers said about half of the 1160 people entered would return for Ironman New Zealand in March on the same course.
Hometown hero Graham O'Grady will look to defend his title in Taupo after winning the 2012 race convincingly in a time of 3h 58m 4s.