The structural engineer took on the technical side, which Fitzgerald admits was overwhelming him, and enabled the business "to charge forward".
"Him coming on board was able to make it viable I guess, or not scarily over the top."
Blackford also shared Fitzgerald's love of the outdoors and vision to give tourists not just a fun day out, but to create a sanctuary for native wildlife and tell the story of the New Zealand bush. Fitzgerald says the experience in a virgin forest gives their operation a point of difference from the two other New Zealand-based ziplines on Waiheke and in Queenstown.
Rotorua Canopy Tours, which opened for business last spring, directs more than 5 per cent of its revenue back into restoring its 500ha Dansey Rd Scenic Reserve base just outside Rotorua.
Fitzgerald says walking down the trap lines in the early days and seeing the predators caught was sobering.
The payback, as well as seeing the return of birds to the forest, is the ability for the pair to extend their offering to include events such as night tours or visits to see a colony of long-tailed bats.
But getting to this stage has been a hard slog.
The two spent several winters of weekends mapping out a path for the high wire adventure that would not disturb the surrounding bush, before chucking their jobs and taking six months to build the structures.
All 12 tonnes of materials were carried in by hand - a process that trimmed 15kg off Fitzgerald's weight.
Even though he had thoroughly researched other ziplines around the world and was able to tap into the experience of North American operators, part-way through the project there was a niggling feeling that it wouldn't pan out, he says.
"I remember even three months into the building sitting at home doing the maths.
"All the saving had gone out of the bank account, thinking: can we pull out now?"
When opening day rolled around, the single-minded focus on the infrastructure meant a mad scramble to get the front office up and running.
Fitzgerald says the first paying customers were an English couple he found by banging on the doors of campervans parked along Rotorua's lakefront.
"When they came back, [by] their reaction I knew that we were going to be okay."
Now, a little over a year later, more than 11,000 people between the ages of 6 and 93 have taken the tour and the experience is ranked the number one activity in the North Island on the TripAdvisor website.
Fitzgerald says it was daunting going into the competitive Rotorua tourist market and offering an experience that - at $129 per adult - is more expensive than other attractions.
Only a helicopter or float plane ride will cost you more, he says.
"What it has taught me is if you create something cool enough and good enough and the perceived value is there, people don't mind paying."