Tide Clocks

[dolabriform]

Hi all
I'm thinking about getting one, are they reliable or just a novelty?
Thanks

 

[Baddox]

I was bought one. It was well made and nicely matched the barometer and clock already aboard. I never fitted it to the boat as it was more a novelty that predictive instrument.

 

[James_Calvert]

We have two, one on the boat, the other at home. They both have the tide hand combined on the same dial as the conventional hour and minute hands.

Being on the same dial can be a bit of a problem, easy at a glance to mistake one short hand for another. I think I'd prefer separate dials.

The other issue is deciding when in the lunar monthly cycle to set the tide time. The clock thinks the time between tides is exactly the same from one day to the next. It isn't. So wherever you set it the clock will be increasingly wrong one way or another, and then less wrong each day, and maybe increasingly wrong the other way and back before repeating the cycle. I don't know whether this error varies according to local geography or not. It is obviously related to springs and neaps. For us we can fix it so it's no more than an hour out one way or another. (Or up to 2 hours out always in the same direction)

So, do I look at them to find out the tide? Not that often. The one at home has a habit of stopping occasionally, and I can't always be bothered to reset the tide hand, given I will probably get the error badly offset.

And the one on the boat is only good for one locality at best.

I quite like having them though. They were both presents to us.

 

[Boathook]

I feel that they are a novelty. I had one for years and it was never "correct" compared with tide tables. When it eventually packed up I never replaced it.

 

[ashtead]

I have a home one but don’t look at it that often . You can replace the unit easily if it breaks down .

 

[wombat88]

The people who sell electric clock movements for those who enjoy making clocks also sell a tide clock movement.

We had one but when the battery ran out I never bothered to replace it.

 

[AntarcticPilot]

I've got a tide indicator on my boat watch. Basically, it tells me very approximately what state the tide will be in when I get to the boat. It only has about 5 divisions, but that's about the accuracy you can expect. It is also only correct(ish) for the place you set it for. Lunitidal intervals are usually only given to the nearest half hour, and as stated by @James_Calvert, it varies through the month. If you want accuracy, use tide tables or a tide app; tide clocks are for very rough preliminary planning.

 

[38mess]

A novelty imo. I had one as a birthday present, it was always wrong even when careful set up. Just get a good set of timetables to be sure.

 

[dolabriform]

Thanks all
I was thinking of getting it for home for the kids to get to know the pattern, but now I feel that hanging a printed sheet by the door will probably do just as well

 

[Daydream believer]

Thanks all
I was thinking of getting it for home for the kids to get to know the pattern, but now I feel that hanging a printed sheet by the door will probably do just as well

But the kids must love Mickey Mouse & Minnie going round. If nothing else they can learn to tell the time. When they get to teenagers you can set LW to 01-00 hours & tell them to be home at midnight, or they are grounded

 

[dolabriform]

But the kids must love Mickey Mouse & Minnie going round. If nothing else they can learn to tell the time. When they get to teenagers you can set LW to 01-00 hours & tell them to be home at midnight, or they are grounded

They're 11 now. I just want to stop them asking me what time high tide is

I think I'll leave a copy of reeds by the front door

 

[Daydream believer]

They're 11 now. I just want to stop them asking me what time high tide is

Questions will change- Just you wait & see

 

[sealegsjim]

I have a tide clock on board which I reset every month. It is pretty accurate and is handy for a quick visual of the state of tide

 

[Stemar]

I was given one. It lived on my office wall for a few years, and was a useful, if approximate, guide to tell me what time to go to the boat. When the clock on the boat died, I moved it on board, where it's a useful clock, but I get as much tidal information from looking out of the window. As a guide to the tide at your home port at home, it's handy but, on board, I'd put it in the same category as those kitchen gadgets that get used a few times then gather dust in a cupboard.

 

[dansaskip]

And the one on the boat is only good for one locality at best.

James makes a very good point here. A tide clock does not give any variation for tidal differences between places. You have only to be a mile or so from where it is set for it to be wrong. So for me just a novelty and I will keep my tide tables (and tidal atlases) thank you very much.

 

[srm]

If you sail in an area with an asymmetrical tide curve it won't be any use. Like the old "rule of twelfths" the machine assumes a symmetrical curve.

 

[AntarcticPilot]

If you sail in an area with an asymmetrical tide curve it won't be any use. Like the old "rule of twelfths" the machine assumes a symmetrical curve.

And, of course, it gives no indication of the actual tidal range.

 

[ylop]

I have a vague recollection on one at the coastguard lookout near my grandfather's house - it was in one of those noticeboards where the information was behind locked glass screens. But I think the CG used to set it everyday so it was "right".

If you really wanted that information now it wouldn't be a massive feat of engineering to use a rapberry pi (a pi zero could do it - perhaps even a pico) with a simple display and pull in actual predicted heights too.

 

[Sandy]

Can you set them for a home port or are they set to high water Dover?

 

[ylop]

Can you set them for a home port or are they set to high water Dover?

You can set them to anything you want - its just a dial with one hand that takes 12h25m to to a full rotation. High tide is usually at the top and low tide at the bottom. Useful for a total amateur to know if the tide is on its way in or out, or how long until the next high / low water but not much of a planning tool.