UKC

I'm a fairly newbie sea kayaker and trying to plan a Christmas paddle for next month. We want to go in the dark so all our Christmas lights will be visible and we want high tide so we can get right up to Lochgilphead. 

Normally, I just Google "Tide Times Lochgilphead" and link comes for a few sites. However, they all only seem to list the next few days. The longest I found was to the end of November. 

Where can I find tide times for Mid December? Presumably they are very predictable so they must have them published somewhere?

Just add 25 minutes onto each high tide. 

more like 50 minutes. however depending on location, a double high or low can affect this drastically so I wouldn't just add on for a month. @girlmonkey this site gives you about a months worth https://www.tide-forecast.com/locations/Poole/tides/latest

Do you have an Android phone?  If so, there's an app called simply 'Tides'.  It doesn't have Lochgilphead as a spot but does have Tarbet or rather "East Loch Tarbert (Loch Fyne)", which should be near enough.

The tides are v predictable, but the algorithms used to predict them are proprietary and tide times more than a week or so in advance tend to be a subscription thing.

For getting a rough guide into the future though, high water in a specific place is generally always roughly the same time of day at a given phase of the moon.  So if you want to know what time high water is six days after new moon some time next year, it'll be more or less the same time as it was six days after new moon last week, or next week, etc.
(Also spring tide will generally be 2-3 days after the full and new moon, neaps 2-3 days after the half-way mark between.  The tidal range is on springs is generally about twice what it is on neaps.)

Looking in Reeds Small Craft Alamanac 2023, Lochgilphead doesn't appear as either a Standard or Secondary port.  Standard ports are those for which very accurate tidal information is calculated. Secondary port information is interpolated from Standard port information.

Other locations in between secondary ports, such as Lochgilphead, require further interpolation of the secondary port information. Which in reality often means guesswork unless you can find a local shop which sells tide tables for the exact location you want.

Greenock appears to be the standard port for Loch Fyne. So you need to know the tide times for Greenock for the dates you want to paddle. You can then add or subtract the times for the nearest secondary port which appears to be either East Loch Tarbet or Inveraray.

East Loch Tarbet rather than Inveraray would appear to be a better bet as its closer to Lochgilphead with a little bit extra added to allow for Lochgilphead being slightly further up the loch.

In reality, high tide times for East Loch Tarbet are pretty much the same as Greenock. Inveraray is about ten minutes after Greenock. So East Loch Tarbet times are probably a reasonable guess for Lochgilphead. This is probably as clear as mud.

Welcome to the wonderful world of tides.

Alternatively if you want to post the dates of your trip I'll have alook for you but accept no responsibility if you end up stranded on the mud a long way from town!

If you plan to get into sea kayaking more seriously the Small Craft Almanac is a very useful book published annually.

Alternatively get your tidal information separately for much less (or for free), and pick up a second-hand slightly out of date almanac on ebay for a couple of quid.  (Or don't bother, and find information about marinas etc. on visitmyharbour.com instead.)

Oh - dur!  That reminds me:
https://www.visitmyharbour.com/tides/228/uk-tables/east-loch-tarbert-tide-t...

Super, thanks! 😊

Thanks for all the detail! Deepsoup came up with a simple version for my simple wee brain!

Thanks, another useful site!

If you are paddling regularly in the same area then this site sells wee booklets & pdfs of annual tide times. https://www.tidetimes.org.uk/ Only £1.80 for 2024, £1.20 for the rest of this year.

We get it for Oban & Dover (for using a tide atlas) and I see there is one for East Loch Tarbert.

Enjoy your paddling.

the tides4fishing website does have free tide times for December (just checked). As mentioned you'll probably have to use nearest location.

Interesting that something so long studied, and so linked to astronomical observation should still be proprietary. I guess that is down to the obvious economic use for cargo. But then (astronomical) navigation is also essential for cargo vessels, and yet that seems to have escaped proprietary methods. Or has it...? 

I use 'absolute tides' on Android. It's about £3 a year for the country's tides times. Slightly more tide ports covered than the tides app.

If you are in the sea a lot, it's worth it. 

Also has the current maps from the admiralty, which can be useful, though can be less effective for kayak closer to shore with local Eddies ... 

if by astronomical navigation you mean knowing where you are on the globe at a given time, then that’s definitely been monetised - nobody really bothers with Astro nav any longer in practice (unless they have a notion to maintain or develop skills etc); they don’t have to do Astro nav because gps chartplotters/ ecdis/ smartphones do it all for you (…until they don’t of course….)

If you’re on iPhone then the Imray tides app is pretty good (requires a subscription). 
 

also Memory-Map app maybe worth getting as you can get the admiralty raster charts, along with Antares detailed chartlets of Scottish W coast anchorages/ narrow channels etc that paddlers and yachties like and admiralty have no reason to survey…

I meant the following high tide is about 25 minutes later, eg 7.30 am, 7.55 pm, 8.20 am, 8.45 pm. etc. 

I did mean old skool astronav. Buy my point was that I didn't think that required anything proprietary.

I know about satnav, and how it is now ubiquitous (I worked on the GSVF-2 constellation simulator we built for ESA...). But those services are provided for free, even if you do need a receiver; those cost bugger all these days. Of course, the likes of W3W are trying to monetise on the back of that free service (as well as countless GIS/GNSS based services).

I dug out a couple of old programs for the Psion 3; Tide98 & Ocean. The readme for Tide is a good primer for why predicting tides is tricky; land tends to mess the tides up, especially the crinkly bits...

Interesting! I had a psion, but didn’t ever think to use it for nav/ pilotage stuff. 
 

I'm far from a mathematician or physicist but find the crinkly bits that affect tides fascinating (even if I don’t fully understand the theory) - eg the amphidrome in Sound of Jura. 

I'm not sure I'm with you, but it doesn't really seem any odder than, say, OS maps being proprietary.  (I don't really understand how the model works that's used to make tidal predictions anyway tbh.)

There does seem to be a huge amount of data on past tide times freely available though, I guess you might be able to correlate those with astronomical data and, if it's also available, perhaps meteorological data to come up with your own predictions?  (Would AI perhaps be a good way to approach that these days?)

https://ntslf.org/data

I just read a book about a man who visited  all the lighthouses in Scotland in his kayak. He worked out his tides by the tide time at Dover. Not sure how though . Will read it again later and let you know.

The OS is mostly surveying; data gathering & processing. and creation of maps. The underpinning mathematical algorithms are not proprietary.

My thought was that it's unusual for navigation algorithms for this sort of basic function to be proprietary (it was the algorithms that you suggested were proprietary).

However, reading the Psion program stuff has reminded me that much tidal prediction is based on gathered data, rather than simply employing simple lunar/earth rotation mathematics. So it may be that it is this data gathering that becomes proprietary, rather like OS mapping.

Of course, the OS financial model is only one way of approaching it; the USGS surveying data and mapping is freely available, based on a different funding model, where government thinks private enterprise can create more national wealth by exploiting publicly-funded surveying work.

Yeah, 'algorithm' is probably the wrong word tbh.

Yes, absolutely.  The moon/earth/sun stuff is simple, on a 'water world' just covered in ocean at a more or less even depth there would pretty much be nothing to it.  But the way the water moves around the land is complicated, sometimes immensely complicated, and the waters around the UK are some of the most 'interesting' in the world as far as tidal currents are concerned.  (Which is one of the reasons several areas around the UK are genuinely world-class destinations for sea kayaking - for example you'd be quite surprised I think, at how far people are willing to travel to paddle around Anglesey.)

About 130 miles? 🙄

The fishermen are your friends. Go to https://tides4fishing.com/uk/scotland/tarbet and choose Dec 25th. You get this:

On Monday, 25th of December of 2023, the sun will rise in Tarbet at 9:09:20 h and sunset will be at 15:31:41 h. In the high tide and low tide chart, we can see that the first high tide will be at 5:55 h and the next high tide at 18:13 h. The only low tide of the day will be at 12:07 h.

So it looks like an afternoon paddle could fit your bill. Nice plan

I've found that site differs by about an hour or more compared to others. Whether that is important is a question that I can't answer for you. 

Shows it calculation plus data. . 

Interesting isn't it. 

I had a Casio watch that used the lat, long and lunar tidal interval to show tides. Quite good, but only showed 8 phases

The trip around the island is nice enough, but with the best will in the world there's no way someone would come to N Wales from, say, Norway to enjoy the scenery.  It's the way the tidal currents interact with the coastline that attracts people from far and wide.

Getting away a bit now from the OP's question, but historical data is actually used in tidal predictions. Using astronomical data alone would only work if the earth had no land masses and was covered by an ocean of uniform depth, there was no inertia in the system and the ocean responded immediately to the tide generating forces, and there was no Coriolis Effect or frictional forces involved.

Rather than consisting of two bulges of water at the sub and anti-lunar points the tides consist of many long "waves" which circulate the earth's ocean basins in an anti-clockwise direction in the northern hemisphere and vice versa in the southern. In the centre of these circulations is a point known as the amphidromic point where the tides are negligable.

As well as Coriolis these tidal "waves" are affected by the depth of the continental shelf areas, the shape and type of coastlines, reflection and refraction from these coastlines, existing wind driven ocean currents, and interaction with other tidal "waves". Things get very complicated where groups of islands exist on the continental shelves. For example, as well as there being a large general circulation in the North Atlantic, the North Sea has three seperate circulations around three seperate amphidromic points.

All these non astronomical bits are usually referred to as the partial tides. The partial tides can only really be inferred from the historical data which needs to be added to the astronomical data. The more historical data you have the easier it becomes to filter out freak meteorlogical data which could skew the calculations. Fortunately there is a lot of historical data.

It's a wonder we can actually predict the tides with any degree of accuracy. Much of this stuff is well beyond the comprehension of my tiny brain!

https://ntslf.org/tides/predictions

Does 28 day predictions.

So good, thank you.