maybe a misprint

I have recently moved to cairns from victoria and I have noticed a difference in the tides here. They normally have the four tide changes as everywhere else although they have a big high and a little high each day(also big low and little low). For sat 5/4 willyweather and also local papers listed the tide changes as in my previous mail. I also witnessed the tides changing as per my email. It was strange to have water right up for most of the day. A mate rang to go fishing, and mentioned the weird tide also as he was confused as to what the times were supposed to be.(he did not refer to tide times only his own observations)
My theory is that the little high and little low had no variation in the heights and therefore became inconsequent. As i'm a newby to qld I am happy to be told otherwise.

Hi Chewytwo.

As Mark says, tides change about every 6 hours or so. It is impossible to have 2 tides in a day...the absolute minimum is 3. But you only get 3 when the "first" tide is just before midnight and the "last" tide is just after midnight.

The times you give do not match anything for Cairns for yesterday...moon, sun or tides.

Are you sure you were looking at tide times ?

For those that are interested. High tides are caused mainly by the moon. The moon orbits every 24 hours and 50 minutes. So tides change every 6 hours 12 1\2 minutes. Here is a paper I just found on it - http://www.astronomy.ohio-state.edu/~pogge/Ast161/Unit4/tides.html

Yes, tides are bigger up that way...Because you are closer to the equator.

EDIT: When I say "impossible" I am of course talking about your location, Cairns...I realise some locations on Earth have two tides per day and some locations can have months or even years between tides.

I just had a look on willy and on BOM. Willy gets their info from BOM.

BOM is clearly wrong. They list the high at 2am, so the next low will be about 8:15am.

Not that I have looked at many, but it seems that weather sites using BOM data all say the same...and reputable sites like this one 😉 are all showing the correct info with 4 tides for yesterday.

Moral...come here first and get it right first time... There is also an app for your smart phone. Maybe Mark could post the link.

I have been told that it was a "neap" tide. where the difference between high and low is less than usual. It may have been that close that there wasn't an actual difference in the water heights. You still technically can call it a tide change although there is no change in movement as the neap tides are matched perfectly. I would think that this would only happen in certain parts of the world. I also thought I saw the same neap tide scenario for Brisbane some weeks later.(not 100% sure)
Neap tides occur twice a month(moon cycle)I will keep my eye out for the next "pefect match"