"I was resolute I was the right person for the job," he said. "But I knew there were other contenders... as well."
The Tauranga-born principal studied in Auckland where he started his first teaching job at Henderson High School in 2006.
He experienced different roles in charge of sport, was head of the social science department and also held a senior management role at the Auckland school.
Sinton moved to Tauranga after securing a role as one of Mount Maunganui College's deputy principals and said he was lucky to have been part of the college for a long time.
His partner was a former pupil of the college, and so was his mother and aunties.
"I wanted to come home," he said.
Sinton said his contribution to the school was going to ensure the excellent work that had already been done remained.
"I have learned a great deal from Russell," he said. "He has definitely left a hole that I won't be able to fill completely, but I can only be me. But I will look to continue his legacy."
Sinton said getting to know the city's youth was what he enjoyed most about being a principal.
"That is a very privileged position to have. I don't think a second goes by when I take that for granted," he said. "It keeps you young."
Sinton was looking forward to seeing the talent at Mount Maunganui College grow as the new principal.
"Every year I shake my head at the talent we have here," he said. "We have sent off 20 national representative's across a range of codes and have been for a number of years now."
Mount Maunganui College principal Russell Gordon had been at Mount Maunganui College for 12 years and served six as principal.
He stood down as principal in July this year to fulfil his new role as principal of Otumoetai College next year.
Gordon said it was a sense of relief when the appointment of Sinton was made.
"I knew the school was being passed on to steady hands," he said. "To someone who has walked our journey for three years."
FIVE THINGS YOU DIDN'T KNOW ABOUT ALASTAIR:
- He is a family man.
- He is an avid surfer - a self-admitted "bad one" but enjoys the surf nonetheless.
- He loves music. He plays the guitar and is learning the drums.
- His favourite food is Japanese and Mexican; he couldn't choose.
- He was born in Tauranga and likes to holiday at a family batch in the Coromandel.
