The former policeman got serious about multisport in 1998 and did his first Coast to Coast the following year, in the two-person category with fellow Bay competitor Neil Hubbard.
Christison started five Coast to Coasts as an individual one-day section and apart from the 2005 one which he didn't finish, because of a heavy bout of the flu, recorded top five finishes in all. In all of the ones he finished, he recorded the fastest time on the mountain run.
"Everyone used to say it was because I had the ideal training grounds out here," Christison says pointing to the mountain ranges above Lake Tutira.
His biggest feat, in the Coast to Coast, was ruining Kiwi legend Steve Gurney's hopes of a 10th title in the 243 kilometre race from Kumara Beach on the South Island's West Coast to Sumner in Christchurch, when he beat him by more than 12 minutes in 2004 with a time of 11hrs33m30s.
"Steve was the toughest competitor I came up against. I was used to turning up and getting mowed down by Steve on the paddle stage. I respected him because he was around multisport for such a long time," Ramblers B grade cyclist Christison recalls.
That 2004 success saw Christison invited to compete in numerous international events for several teams including the American-based Team Nike.
"It was good to have that experience. Most of the competitors I was up against were full-time professionals ... there weren't too many others like me who had a full-time job as well as four children.
"It was good to do it when I was in my prime because a lot of my expenses were covered by prizemoney. I could not afford to do it if I was only doing it for the love of the sport."
China, Borneo, South Africa, Portugal, the United Arab Emirates and Australia were a selection of countries which featured regularly in his passport. The Portugal event in 2009 was his toughest.
"My health wasn't right and I had no energy. The bottom of my feet were blistered and, for three days, I was running on raw feet. It was one of those races, run under a new format, where you never knew where you were coming until you crossed the finish line.
"I was the weak part of the team and in a lot of pain. It was my hardest race because I suffered the most and normally I'm one of the strongest ... that was a dark place for me because I didn't want to let the team down. We finished second," Christison recalls.
The China race was his favourite.
"It was more athlete-friendly, one of those stage races where you raced for six hours and got to go back to your hotel each day to rest and recover."
It will be a surprise if one or two of his four children, 17-year-old Shamus, 16-year-old Bradley, 15-year-old Thomas and 11-year-old Susanna, don't do a Coast to Coast in the future. All four have done Hawke's Bay Triathlon Club events and they have also swum for the Napier Aquahawks club.
Bradley is a former national under-14 cross-country champion, national 3000m champion and national age-group triathlon champion.
"It's good to see them being active," Christison says.
He couldn't complete this chat without thanking his No 1 supporter and wife Kirsty for all her support.
"I would not have been able to do everything I did without her approval."
She also helps Christison with his management work. They look forward to the arboretum's public open days, which are limited to Sundays between October and May.
No doubt there won't be too many of those days let slip past without conversation about Christison's glory days.