Those who have yet to vote, should at least inform themselves of what transpired overseas following legalisation of SSM. For example, see what transpired in Canada and the UK:

A Warning from Canada: Same-Sex Marriage Erodes Fundamental Rights, Dawn Stefanowicz, The Public Discourse, 24 April 2015
http://www.thepublicdiscourse.com/2015/04/14899/

What’s changed in Britain since same-sex marriage?, David Sergeant, The Spectator Australia, 7 Sep 2017
https://www.spectator.com.au/2017/09/whats-changed-in-britain-since-same-sex-marriage/

It may come as a surprise that the unstated objective of homosexual activists is to destroy traditional marriage:

Homosexual Activist Admits True Purpose of Battle is to Destroy Marriage, Micah Clark, Illinois Family Institute, 4 Jun 2013
https://illinoisfamily.org/homosexuality/homosexual-activist-admits-true-purpose-of-battle-is-to-destroy-marriage/

Sodom and Tomorrow, Geoffrey Luck, Quadrant Online, 29 Sep 2017
http://quadrant.org.au/opinion/qed/2017/09/sodom-tomorrow/

It should be noted that not voting is equivalent to voting 'yes'.

//It should be noted that not voting is equivalent to voting 'yes'.//

This is why we need better civics education in schools...

No it's not. It's equivalent to abstaining.

Not voting at all is the equivalent of voting YES because each abstainer is one less hurdle against he virulent cultural Marxists who are determined to undermine our society and replace it with something really vile and totalitarian. Not voting is dumb, cowardly and indicative of what a really stupid person you are.

Dear Yuyutsu,

There will be no "new" definition of marriage.
What there will be will be civil partnerships and
contractual relationships - because every single
Australian - gay, or straight deserves to be
treated equally in the eyes of the law and in the
eyes of our society.

Dear Foxy. Why waste your time casting pearls before the, oink, oink oinkers?

You've less chance with these oinkers than Richard Brampton?

Who reportedly offered a highly place member of the flat earth society free trip into near orbit, in one of his rocket planes?

As they rose and a ovoid world was laid out for the ultimate cynic to see with his own eyes! As he digested the G forces of take off, the weightlessness of decent and so on?

Only on landing to congratulate Sir Richard on the stunning graphics and even more stunning special effects?

As always with some of the patently brain washed? Particularly those whose average IQ is roughly equal to the ambient temperature?

Appealing to reason, logic or a huge body of evidence, is just a waste of valuable time!

Even should the yes case win by a massive majority? They will invent all manner of conspiracy theories etc?

For them nothing will have changed, except their ability to discriminate and or inculcate their fact free fiction into young gullible minds, to create more clones who fatuously and falsely think as they so clearly do!

Left handedness is not something the left handed chose! Nor anything else created in the womb and transferred, just like left handedness, by genetics!
Cheers, Alan B.

Raycom: "It should be noted that not voting is equivalent to voting 'yes'. "

As Toni Lavis already pointed out it is abstaining (Well in most cases anyway- in a small number of others it may be something like not being able to vote, such as being overseas for the last 2 months, or maybe just general apathy or other things)

So let me give you a couple of hypothetical situations which may change your stance:

1) Consider an opposite case- What if the question was posed the opposite way, ie., it asks whether you DON'T support same sex marriage. In this case would you consider all non-votes to be yes votes for this question?

2) Consider a different question- Let's say you're a French citizen a few decades in the future where due to immigration and breeding the Muslim's now make up the majority of the population. During this time Citizen Initiated Referendums at the national scale were introduced. The following question was initiated for voting on "Do you support strict sharia law, (ie: we will kill all the gays, adulterers, atheists and many others. Chop limbs of thieves. Enslave the women. etc... )". Now the results were: 50.0001% of respondents said yes but only 85% of the population voted. Would you accept this as a win for the YES vote?