Fett has been checked annually from age 35 and about a year ago he received the same diagnosis.
But Fett is reluctant to make this a story about himself.
"There are 100 different people going through the same thing."
While he is still taking some medication, he is almost in the clear after a bout of radiation.
"What I've learned is basically you need to have an advocate. You have to push to get a diagnosis and treatment.
"My aim is to encourage people to get checked because not every GP suggests, you actually have to ask.
"Everyone's different, there's no blanket treatment so listen to the experts. Ask the experts, as many as you can."
The walk will be the third one organised by the Rotary Club of Rotorua Sunrise, of which Fett is a member, as was Gunn.
"It is meant to be the fourth but we had to cancel last year because of Covid," Fett said.
"Normally it's Blue September but we've missed out on September twice because of Covid so we said we'd just do it."
Fett has picked such an aspirational fundraising figure because he wants to set up Prost-FIT exercise classes specifically for men before, during and after prostate cancer treatment.
The exercises are specific and include pelvic floor strengthening, cardio and strength training. Setting this up would need funds and a gym to buy into it.
Fett said while there were a few prostate cancer support groups around, some men were not good at seeking support.
"They are much better at going to a gym class then turning that into a support group and they also have the benefit of getting the right fitness."
The Prostate Cancer Foundation NZ said prostate cancer is the most common for Kiwi men. One in every eight men will develop prostate cancer in their life and 10 are diagnosed every day.
In total, more than 4000 men are diagnosed with prostate cancer every year - more than breast cancer diagnosis rates. Of those, more than 700 die.
Cash and eftpos will be available on the day of the Blue Walk and donations are also being accepted online for a few months.
The Blue Walk
What: The Rotorua Blue Walk organised by the Rotary Club of Rotorua Sunrise followed by a talk about prostate cancer from a local GP
When: May 11, from 5.30pm
Where: Starts and ends outside Hennessy's Irish Pub, wear as much blue as you like
Cost: $10 entry, kids under 12 koha, cash and eftpos available