But Drumm's message in the newsletter, titled "Hope not dope", is clear - young people need to be protected from easier access to cannabis.
"As a school community this year, we have spoken a lot about hope as an essential value
in the toolbox of a MAGS student. As the world has wobbled, our young people have rightly looked to the adults in their lives to provide the guidance and wisdom to help navigate a purposeful way forward.
"That guidance and wisdom is needed now, more than ever, as we address the disturbing prospect of a future for our young people where cannabis is legalised."
Drumm wrote of his concern at the "seemingly frivolous approach of some commentators" to the referendum.
"The overwhelming evidence of the disastrous impact of cannabis on the young brain has been dismissed and even been a source of humour for some.
"Despite some arguments to the contrary, it can never be okay for a young person to get 'stoned', 'wasted' or 'high'.
"And the impact on learning? ... It's not called 'dope' for nothing!"
In a legalised and normalised cannabis environment, that message was going to be much harder to sell, he wrote.
"And if we think that the government and authorities can police underage access to cannabis, just turn up any given Saturday night to a party of 15-year-olds and see how effectively alcohol and vaping laws are being enforced!
"More than ever we need young people fully present and engaged with friends and
family – choosing getting into life rather than getting 'out of it'! I trust New Zealanders will put those young people first tomorrow.
"I'm backing hope to be the winner on the day!"
A 1 News Colmar Brunton poll yesterday showed 41 per cent of respondents were for cannabis being legalised and 51 per cent were against.