View Full Version : Tide Times-reliability of instruments,

10th Jan 2013, 00:16
As a peeps who spends a considerable amount of time on the North Cornish Coast, it's quite important that I have a handle on the tide times-for 2 reasons:

I don't have to walk too far to the tide edge whilst carrying heavy surfboard designed to carry fat gingernut.
To ensure gingernut and gingerettes don't get cut off by tide whilst walking into town.

Mrs G has bought me a posh (Casio) watch, have had to pre-set time, longitude and interludal interval (!) Now my question is this, is it as trustworthy as my old yellow book Newquay Tide Times | Tide Times (http://www.tidetimes.org.uk/newquay-tide-times)
which is accurate, to the minute, time after time.

My life could depend on this:)

10th Jan 2013, 00:43
I would go for tide tables or admiralty website if you possibly can. The watch should be ok but I'd want to check it against the tables for a week or two before fully trusting it.

The tide can never be relied on to match predictions, time doesn't vary much but low pressure and onshore winds can up the level by a couple of metres.

I use two admiralty links, one set to today so I can see times and another set to the next seven days so I can see the pattern. Both are set to my nearest port. I've set the links below to Newquay.

It is important to allow for bst/dst.

Show Prediction (free) - Newquay 10/01/2013 for 1 day - EasyTide (http://easytide.ukho.gov.uk/easytide/EasyTide/ShowPrediction.aspx?PortID=0546&PredictionLength=1)

Show Prediction (free) - Newquay 10/01/2013 for 7 days - EasyTide (http://easytide.ukho.gov.uk/easytide/EasyTide/ShowPrediction.aspx?PortID=0546&PredictionLength=7)

10th Jan 2013, 01:04
A quick check on the casio website seems to show it takes tides from the nearest city in its database. It offers a 'correct high tide time' as compensation.
You would need to find out the nearest city in its database, and check the tidal curve matches your location. If so, the correction would be valid. If not, stick with the Admiralty stuff Mike's given you.
I do not not know the cities in the database, nor whether the watch uses the actual curve for each city or a simplified one based on moonphase.
You could check by taking the reading every hour for 13 hours, then matching the data to the admiralty curve for the named city.

The manual I've checked seems to show only one city in the UK - London, but I don't know your watch model number.

So unless the London curve matches Newquay, and a very quick check seems to indicate it doesn't, stick with the yellow book/Mike's stuff.

green granite
10th Jan 2013, 07:47
Just remember the rule of 1/12ths, not dead accurate but near enough for your purposes.