Mr Henderson's advice for new teachers? "Forget the bullsh**t."
"Get on and enjoy the classes, enjoy the teaching, enjoy the students, that's what it's about. Kids only want to realise that you care about them."
In almost four decades, Alan Galletly saw the introduction, development and evolution of IT in the school.
I had a young lady in my Year 9 science class that came up to me at the end of the lesson and said, 'Do you realise, sir, you taught my grandparents?'
His highlight was his involvement with students outside the classroom, especially coaching hockey and seeing four of his hockey players selected for the Black Sticks and two end up at the Olympic Games.
Doreen Swetman was overwhelmed by the size of the school when she first arrived but said she soon found her feet.
Her teaching policy entailed starting each day anew.
"If they've had a rotten day the day before, we don't carry it on, we don't remember it, we learn from it and we don't go back over it. The room has to be a safe place."
"You become that one stable factor for the kid in the classroom."
Social studies head Larry Dixon said one of the most significant moments of his career happened last week when he bumped into two ex-pupils in Wellington.
When they stop and talk to you and tell you how they're doing it makes teaching worthwhile.
"The number of kids I've taught in this school is in the thousands. While you don't always remember their names you remember them, and they remember you.
"When they stop and talk to you and tell you how they're doing it makes teaching worthwhile."
Anna Shaw said it had been an interesting journey seeing the changes to the computing department. She said it was the people who made Otumoetai College what it was.
"I always felt really comfortable here. When I first came here for my interview, there was something about it I liked."
Textiles and design teacher Julie Eagle said she enjoyed seeing how her students developed over the four years she spent with them.
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"You become really proud of them and really close to them."
Colette Mackenzie started as a relief teacher and ended up in the careers department teaching Gateway. Her highlight was being a form teacher of the Maori students.
"It's been fantastic to watch them grow and develop and leave with some high expectations."
Principal Dave Randall said he had never seen seven permanent staff leave at the same time, let alone retire.
"One fortunate thing is the school has a good reputation, Tauranga attracts people, so it hasn't been that hard to replace, but it's that experience and it's the in-school knowledge."
Service to Otumoetai College
Doreen Swetman: Young Enterprise & computing. 31 years at Otumoetai College
Julie Eagle: Textiles and design. 11 years
Larry Dixon: HOD social science. 28 years
Stewart Henderson: Physics and science. 45 years
Alan Galletly: Assistant head digital business faculty. 37 years
Anna Shaw: Computing and "rowing mistress". 22 years
Colette MacKenzie: Pathways department, Poutama form class. 7 years