Sailing in Scottish Islands

+1. I'm not knocking the charts, or the fantastic effort that Bob has put in. They fairly show up the UKHO who are still issuing charts, parts of which are based on original surveys carried out in the 1840s.

I suppose it's understandable that the UKHO is mainly interested in places where commercial and naval ships might go. That said. many of those old charts are a darn site better than the ones they issue now. Compare the level of detail in the 1848 chart of Tobermory

byrpzxRl.png


with the current one

1od14y4l.png
 
I don't use Antares. They truly are excellent but I just love the sound and feel of a decent rock nudge

I have them but have found too many significant difference between them and reality to use them for more than guidance. Which, to be fair, is wholly in accordance with Bob's disclaimer.
 
I have them but have found too many significant difference between them and reality to use them for more than guidance. Which, to be fair, is wholly in accordance with Bob's disclaimer.

Do you have any examples of these “significant differences” you refer to, as very interested to know.

It is certainly not my experience so far. I have found Antares very reliable. It I have probably only used 100 or so of them, so that leaves 80% unvisited.

On another thread you said you use Antares as simple images rather than using within plotter software such as Memory Map. Could this be a factor?
 
I suppose it's understandable that the UKHO is mainly interested in places where commercial and naval ships might go. That said. many of those old charts are a darn site better than the ones they issue now. Compare the level of detail in the 1848 chart of Tobermory

byrpzxRl.png


with the current one

1od14y4l.png

My preference is for the modern version; I can't easily read all those spot depths but I can easily tell where there's more than 5m and most of the time, that's what I really need to know.

Derek
 
At Tobermory, unless filling with a large quantity of diesel, get your cans filled with white at the garage. White benefits from the island subsidy which red doesn't attract.

Further to above, they no longer fill containers on the pontoon, they send you up to the garage, there is a 'gas oil' pump there behind the road diesel pump but last summer I discovered that a clean container I filled there had black bits floating in the bottom of it. I suspect that this may be because of low through put on this pump. So in Tobermory I would strongly recommend following Awol's advice. Saves time filling in the stupid 'declaration' too.
 
I gather that the Cruising Association are holding an information sharing / briefing day on this very topic on Saturday 25th January at CA House in London. Might be of interest to you (or others)?

nice tip, thanks for mentioning this, I keep meaning to rejoin the CA... probably will now - I'm applying for leave to attend (from wife & kids).
 
Further to above, they no longer fill containers on the pontoon, they send you up to the garage, there is a 'gas oil' pump there behind the road diesel pump but last summer I discovered that a clean container I filled there had black bits floating in the bottom of it. I suspect that this may be because of low through put on this pump. So in Tobermory I would strongly recommend following Awol's advice. Saves time filling in the stupid 'declaration' too.

If there's a low throughput on the red diesel pump at the garage, it's not surprising. Have you seen the price on it? IIRC it's something like £1.75.
 
If there's a low throughput on the red diesel pump at the garage, it's not surprising. Have you seen the price on it? IIRC it's something like £1.75.

Avoid it. The profit margin they are taking is a joke. Bulk marine diesel is circa 70p/litre, pre any tax.
 
If there's a low throughput on the red diesel pump at the garage, it's not surprising. Have you seen the price on it? IIRC it's something like £1.75.

I was charged £28.98 for 22 litres,think that is closer to £1-30, I bought the same amount from Highland Council at Flowerdale Pier for £19.98 ( 91p) later at Corpach, (Scottish Canals) the price was £1.20. So prices were quite a bit higher everywhere this year. I do expect to pay more for anything I buy on an island except fish.
 
nice tip, thanks for mentioning this, I keep meaning to rejoin the CA... probably will now - I'm applying for leave to attend (from wife & kids).

The Cruising Association can be very helpful so worth rejoining - but if interest to you, or any others reading this thread, the CA seminar on Cruising the West Coast of Scotland is open to non-members (£40 incl lunch) as well as members (£32). It is on Saturday 25th Jan, 10am-5pm at CA House, London. Needs prior reservation online or vIa the CA office
 
Do you have any examples of these “significant differences” you refer to, as very interested to know.

From memory only ... I think he significantly underestimates the depth of the notorious shallow bit in the channel at Arisaig and his version of Acarseid Mhor on Gometra seemed rather odd. My suspicion is that the algorithm he uses to convert from spot depths to contours is not terribly reliable. Having done that professionally (stress contours, not depths) I appreciate that it's very difficult, particularly when you have rapid changes and irregular grids.

They are certainly very useful, and he has done an amazing job in producing them, but I do think that particular caution needs to be exercised, especially around outcrops and other small areas with rapidly changing depths.
 
My preference is for the modern version; I can't easily read all those spot depths but I can easily tell where there's more than 5m and most of the time, that's what I really need to know.

I agree that the modern one is easier for some purposes, but the old ones can be better for anchoring or finding your way around tight places. I used Tobermory as an example because I could screenshot the modern chart from visitmyharbour; there are plenty of other places where modern charts have very little detail and the older ones have oodles.
 
If there's a low throughput on the red diesel pump at the garage, it's not surprising. Have you seen the price on it? IIRC it's something like £1.75.

Unrelated, really, but the summer before last I was on a pontoon at Tobermory when one of the universities' navy boats refuelled. There was something wrong with the pump, which took eight hours to top them up. Not the most peaceful stay I have ever had anywhere.
 
...Then, of course, there are the natives. These posts have included invitations from some to visit their fiefdoms. A review of "The Wicker Man" film may explain why!
Some will charge a bottle of gin even for just anchoring nearby!

...Don't rely too much on electronic charts at big magnification - they are based on old surveys with a dubious datum (although Antares are spot on). Mk1 eyeball is quite good.
This is probably the most important navigation advice for the west coast. Having said that it is no more or less difficult or hazardous than most other areas in the uk. Possibly the biggest difference is the remoteness and greater self sufficiency requirement. There are some sizeable VHF blackspots.

I have them but have found too many significant difference between them and reality to use them for more than guidance. Which, to be fair, is wholly in accordance with Bob's disclaimer.
Used them on MM for at least 6 years and yet to fin any errors. Accurate enough to clean the bottom of the keel on a sand bar in Loch Skavaig! :rolleyes:

As to Diesel, I avoid the few marinas due to high prices and low throughput as noted by Quandary. Locations that I have used or not;
  • Tobermory - avoid like the plague, price!
  • Kyle of Lochalsh - buy direct from the Highland Council pier in cans. Good price and clean. Cash only
  • Gairloch (Flowerdale) - ditto
  • Uig - use cans from the commercial pier (clean and best price). Cash only
  • Stornoway - from the garage about 200yds in cans.
  • Mallaig - ditto
I generally carry 4 20l plastic cans which allows plenty of options when there is no wind.

Oh, and you need a good anchor with at least 50m of chain, but that’s another thread...

Regardless of all the comments here, just come up and enjoy it not forgetting to let us know so that we can extend our welcome.
 
I was charged £28.98 for 22 litres,think that is closer to £1-30, I bought the same amount from Highland Council at Flowerdale Pier for £19.98 ( 91p) later at Corpach, (Scottish Canals) the price was £1.20. So prices were quite a bit higher everywhere this year. I do expect to pay more for anything I buy on an island except fish.

Back in 1989, petrol on Colonsay was over a pound a litre when it was around 35p everywhere else ...
 
Another feature to note is that 2020 is the Year of Coasts and Waters in Scotland. West Coast Waters is part of it. I know it's a tourist board initiative but I can't work out what it's about.

Derek
 
From memory only ... I think he significantly underestimates the depth of the notorious shallow bit in the channel at Arisaig and his version of Acarseid Mhor on Gometra seemed rather odd. My suspicion is that the algorithm he uses to convert from spot depths to contours is not terribly reliable. Having done that professionally (stress contours, not depths) I appreciate that it's very difficult, particularly when you have rapid changes and irregular grids.

They are certainly very useful, and he has done an amazing job in producing them, but I do think that particular caution needs to be exercised, especially around outcrops and other small areas with rapidly changing depths.

As others have said, if you have observed any issues with Antares Charts then you should report them back to Antares so they can be checked.
I am not familiar with Gometra North Harbour, but Antares looks to be consistent with but much more detailed than the official Admiralty chart. So not sure what you feel is “odd”.

I have been into and out of Arisaig a few times using Antares and not noticed any discrepancies, having checked depth by going directly over a few spot soundings in the approach to check actual tide height (although stuck to a narrow channel so not explored a lot). But I don’t see why you say Antares “significantly underestimates the depths” in the narrow channel - i.e. you are saying it is in fact deeper than Antares indicates. But from what I can see:
- Navionics gives no detail, so take your choice of minimum depth between drying 1.5m and drying 0.2m
- Admiralty BA2207 again gives no detail, with minimum depth of drying 0.2 - but before relying on this, it is difficult to tell exactly which source but looks like the survey was leadline type between 1857 and 1866 !! (Do you feel lucky)
- The old Martin Lawrence Guide didn’t seem to commit to a depth but implied could find about 1m if zig zagged round drying rocks
- Current CCC suggests a minimum depth of 0.4m - but probably now based on Antares data rather than 19th Century surveys
- Antares shows a route “technically” with minimum 2m depth, but strongly advises not assuming this but 0.4m controlling depth, as deeper gap far too narrow to keep in reliably with tide.
On this basis Antares, rather than underestimating, is showing a tiny bit more depth than other sources. But all best done with a couple of metres or more of height of tide to be on the safe side.
 
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