A second strike has also been threatened to raise key messages including a need for more time to teach, a pay increase and more funding for children in learning support.
Robertson had been thinking about leaving the profession for a couple of years before making a final decision in Term 1 this year.
"It got to the stage where I felt I needed to do something different and Kaimai School needed someone new to come in," he said.
"But also New Zealand's education is in a situation where they are not getting the teachers coming in, and the teachers are leaving."
In a career spanning more than a decade, Robertson said the most significant changes included a decreasing number of applicants, rising school rolls, and resourcing and funding which hadn't kept up with the needs of "high needs" students.
"It feels like as a principal you are battling for the teacher, the student and the student's family. There is just no money there, that's basically what it comes down to."
Kaimai School's roll on Robertson's first day was 74 which had now climbed to 109.
Robertson believes Tauranga had reached crisis point about two to three years ago.
"You are getting students crammed into classrooms, using libraries as a classroom ... people can't get enough staff," he said.
To make the profession more desirable was simple in Robertson's mind. "Pay".
"I was listening to the radio advertising for tow truck drivers in Auckland earning up to $90,000 which was about the same as what I am earning," he admitted.
Robertson also said "political ideology" needed to be removed from education.
Tauranga MP Jan Tinetti was "gutted" when she heard Robertson was leaving the profession.
"He is an amazing person and principal," she said. "I know that is happening to a lot of people out there. The job of being a principal is the most complex and most difficult job."
Tinetti, who was a principal for 30 years, was concerned about the expectations of workloads on principals.
"We are just not going to get people into those roles if we carry on this way," she said.
However, Tinetti said throwing money at the problem would not stop the "burn-out rate".
"It is not an overnight fix," she said.
Education Minister Chris Hipkins would not comment on individual circumstances but said the Government was committed to "rebuilding education".
"We value the work that principals and teachers do. We are listening and are sympathetic to their concerns," he said.
However, Hipkins said the "financial bucket" was not unlimited and "we can't make up for nine years of underinvestment all at once".
"We are offering teachers double the pay increase, on average, compared to what the previous National Government offered.
"But we also recognise that pay isn't the only concern teachers have raised."
Ministry of Education deputy secretary of early learning and student achievement Ellen MacGregor-Reid said the Ministry was currently at the bargaining table about primary principals' pay and conditions.
"Teachers and principals do a really important job and we value the work that they do," she said.
"We recognise that concerns have been raised about workload and wellbeing issues."
A New Zealand Education Institute spokeswoman said NZEI was not responding to anything that could be part of the negotiations at this time.
Kaimai School's board of trustees could not be reached for comment.
RELIEVING PRESSURE:
The Government had relieved pressure on schools by:
- Increasing the operations grant for schools
- Increasing support for kids with additional learning needs
- Reducing teacher workload by abolishing national standards
- Introducing an emergency teacher supply package worth $9.5 million within two months of coming into power and then a further $20min Budget 2018 to continue supply initiatives
- This year's Budget included $272m for learning support, $59m for teacher aides, and $394m for new schools and classrooms.
- $370m was also set aside for 1500 new teaching places by 2021 to meet population growth.
Source: Minister Chris Hipkins and Ministry of Education
GOODBYE DANE
He has been 'Mr Robertson' for 10 years, now the pupils at Kaimai School can just call him 'Dane'.
Dane Robertson is calling it a day after a decade as principal of Kaimai School.
As of Monday, the 43-year-old will instead walk through the school gates to pick up son Cole, 9, as Dane, the "dad".
"It will be quite nice," Robertson said.
His newfound spare time will be spent making the odd craft beer, cooking, rowing and setting up a non-profit organisation supporting elite athletes through transitioning from sport to the real world alongside brother-in-law and Olympic gold medallist Eric Murray.
Robertson said he was sad to go. "I love the kids and the community," he said.
As he sits in his office on his last day dressed in ripped denim jeans and blazer, the outgoing principal reflected on a 15-year education career.
Robertson took his first footsteps on the Kaimai School grounds in 2008 when he applied to be a senior teacher.
"I was just waiting in the foyer, there were no students here at the time it was just the staff," he said.
He was teaching at Katikati College and had popped in to meet the then principal Neil Towersey.
"I just picked up a feeling in the school even though there was just the staff there," he said. "There is a nice feeling; there is a nice vibe about this school."
One of the first things he did at Kaimai School was score funding to provide a laptop for each senior pupil.
"Within the first year we had laptops for every student and have kept that up for 10 years," he said.
Robertson also helped to initiate the idea of a new skatepark at the school which replaced an eight-year-old rusted playground.
The school's Parent Teachers Association raised nearly $50,000 for the new skatepark and gained grants from pub charities, Tauranga Energy Consumer Trust, NZ Lotteries Commission and Rotary Club of Tauranga Sunrise.
"That is something I am really proud of," he said. "It helps build resilience with the kids, confidence, and co-operation."
In 2011/2012 Robertson joined the Western Bay of Plenty Principals' Association before he was nominated as the association's principal in 2014.
There, he helped to bring international speakers from America and Australia to Tauranga, take principals across the Western Bay and Tauranga to Christchurch, Wellington and, this year, Melbourne for professional development and organise social outings such as bowling.
"I am really proud of what we did there too. It is quite an isolating job being a principal because you're it," he said.
"One of the things I have learned as a beginning principal is they are not your problems, they are the jobs problems. If you don't have a strong connection with your colleagues, you think, 'What am I doing wrong?'."
Despite the pressures that the New Zealand education was facing, Robertson would still have chosen to become a teacher if he had known what he knew now.
"I would still do it. I could probably just about name my first class, and they would be in their mid-20s now," he said.
"I think that is what as a principal you start to forget is why you got into it in the first place."
ROBERTSON'S HISTORY:
2000: Moved to Tauranga from Oamaru.
2003: Started working at Katikati College. Roles: Year 7 teacher, Year 8 dean and numeracy project leader
2008: Started at Kaimai School as a senior teacher
2009: Acting principal of Kaimai School Term 1. Became Principal in Term 2.
2011: Joined the Western Bay of Plenty Principals' Association
2014: Nominated as president of the Western Bay Principals' Association
