Anyone know anything about tides?

Why is the low tide at 3 points reasonably close to each other on the coast so different? For example, say this afternoon the low tide at Kaikoura is 2pm, at Akaroa it's 1pm and at Lyttleton it's 1:45 pm. There's no tidal information for the beach I want it for, so I kind of guess based on the above, but Akaroa is in between Kaikoura and Lyttleton, but it's got the earliest low tide.... very confuzzled...

Andrea
Oxford

distance eastwards to some point, also how directly exposed to the sea the measuring point is, and the slope of the seabed. It's complicated.

It all depends on the Ocean Currents Andrea, and the directions they circulate in. For some parts of the globe it's in a clockwise direction, and other places anti-clockwise. I would be picking that the effect of Banks Peninsula will have something to do with it.

On a straight-ish piece of coastline such as Kaikoura to Northern Canterbury, you would expect the times to be in very close proximity to each other, but when a peninsular or other non-straight piece of coastline gets in the way, the swirling effect of the Ocean's Currents will produce significant variations in the High and Low Tide times.

If you want to have a more accurate prediction of the tide times for your area, you can use this program:

www.wxtide32.com/

As you can see from the website, it has:

• More than 9,500 stations worldwide.
• User station manager to easily add custom tide and current subordinate stations.

By entering your own map coordinates (available from a GPS or LINZ map), it should be possible to get accurate tide times for your area.

I use this program as part of the Weather Display software which runs my weather station. It has always proved deadly accurate at our place.

Thanks for that, Kiwi and Grant. That makes a lot of sense, and Akaroa is a penisula, while Lyttleton is in a horseshoe-shaped harbour.

And thanks for the programme info. DS is looking forward to having a play with it when he's done with his exams.

Cheers
Andrea
Oxford

the current goes up the coast, starting at Rakaia, then it swirls round the peninsula and up to Kaikoura. There is a very good satilite image somewhere showing how the sediments get deposited. You can see them being washed round.