New Loch Etive Charts and Imagery

A few months ago I mentioned that the UK Hydrographic Office was releasing survey data for many areas which contained much more detailed information than the standard charts from Navionics, etc. When I checked back on their website recently I noticed that a full survey is now available for Loch Etive, mainly using a 2m x 2m grid.

I downloaded all the data and ran it through Reefmaster to generate a full set of AT5 Etive charts for my Lowrance chartplotter, plus a set of images that might be of interest to anyone fishing Etive. The shallower areas are charted with a 25cm contour, whilst deeper areas have a 1m contour spacing – so there is a lot of detail in there.

To cover both my ass and yours I need to make it clear that these files are not intended to be used for navigation, but to help you identify marks to fish and get a better understanding of the loch. There isn’t really very much to hit in Etive, but don’t blame me if you do!

If you just want to look at an enlarged version of the images below then click on these to download the larger version. These are quite large (6-14 MB each) so may take a little while. Then just open in Photo Viewer or something similar and zoom in to the areas of interest to you.

Reefmaster chart of Loch Etive (from the mouth of the loch to the Abbots Isles area) using UKHO survey data (9 MB download)
Reefmaster chart of Loch Etive (from the mouth of the loch to the Abbots Isles area) using UKHO survey data (9 MB download)
Etive Charts - Reefmaster generated chart of Loch Etive (from the Abbots Isles to Ardchattan area) using UKHO survey data (10 MB download)
Reefmaster chart of Loch Etive (from the Abbots Isles to Ardchattan area) using UKHO survey data (10 MB download)
Etive Charts - Reefmaster generated chart of Loch Etive (roughly the area from Airds Point to Bonawe) using UKHO survey data (13 MB download)
Reefmaster chart of Loch Etive (roughly the area from Airds Point to Bonawe) using UKHO survey data (13 MB download)
Etive Charts - Reefmaster generated chart - Bonawe Quarry to Cadderlie (12MB)
Etive – Bonawe Quarry to Cadderlie (12MB)
Etive Charts - Reefmaster generated chart of Loch Etive (roughly Cadderlie to Kinglass area) using UKHO survey data (12 MB download)
Reefmaster chart of Loch Etive (roughly Cadderlie to Kinglass area) using UKHO survey data (12 MB download)
Etive Charts - Reefmaster generated chart of upper Loch Etive using UKHO survey data (6 MB download)
Reefmaster chart of upper Loch Etive using UKHO survey data (6 MB download)

The main problem with the images is that is difficult to relate them to a specific feature or place in Etive. However, if you are a Google Earth user you can download the KML files below and save them in the same folder as the image file (i.e. download the image file(s) first, before the equivalent KML file). Then simply double click on the KML file to open Google Earth and load the image file alongside the Google imagery. The files may take a few minutes to load properly, so best to go get a coffee at this point.

Entrance to Loch Etive
Abbots Isles to Ardchattan
Airds Point to Bonawe
Bonawe to Cadderlie
Cadderlie to Kinglass
Upper Loch Etive

I haven’t uploaded the Lowrance AT5 files yet because (a) I haven’t checked them out myself and (b) they’re created for my older Lowrance chartplotter rather than the newer versions and (c) I need to sort out instructions for using multiple AT5 files on one card. Everything should work OK on newer kit than mine but with fewer features, and I’ll probably pop the files up at a future date.

A little update…

I’ve added a few more images, most of the area from Bonawe Narrows looking NE up Loch Etive, which show the some of the same information with a 3D view. They are scaled down from the full sized images, but might still take a few seconds to load.

3D Reefmaster view of Bonawe, Loch Etive

The underwater cliffs on the right hand side of the image are roughly where the fish farm is (a popular mark which throws up quite a range of fish), opposite the main quarry.

This next one is an export view from Reefmaster of the same chart. The KML file to use with Google Earth is here.

Relief view of underwater trench near Bonawe Narrows, Loch Etive

And this shows the results after embedding the previous file in Google Earth using the KML file – it makes it much easier to locate yourself within the charts (and you can zoom, etc. as you would normally in Google Earth).

Google Earth view of 500 foot deep trench NE of Bonawe

And a final image of quite an interesting little feature near Ardchattan, which looks like an old esker ridge left over from the ice age. I don’t know whether any of this really helps catch any more fish, but it does boost confidence a bit, and feeds my general fascination with maps and charts!

A possible Esker ridge at the bottom of Loch Etive

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Re-visiting Etive

It’s been weeks since I was last out, and it’s been frustrating watching a shedload of wet and windy weather blasting through on any available free time. However a calm sunny day was forecast for the Etive area so I decided to combine that with an over-nighter boat camping well up the loch.

Early winter snow near Barrs
Early winter snow near Barrs

Launching in the dark was no big deal, but ploughing up the loch by chartplotter proved a little more challenging, especially as my Navionics card pre-dates the upper loch being converted to electronic format. Darkness, low cloud and light rain misting up your glasses disorientates you quite easily, so I was glad I know the loch fairly well and had a few waypoints set.

Setting up camp was reasonably slick and I was heading back out onto the loch in well under an hour, setting up stall in one of my favourite deepwater marks. The rain wasn’t heavy but did manage to chill everything down quite well, and action was on the slow side. I gave it a couple of hours with a few small spurs, a ray and dogfish to show for my efforts, before heading back ashore to get some dinner organised.

Overnight at Barrs
A cold night at Barrs

The fire and little BBQ provided a little relief from the cold, and clouds began to break and reveal the moon. Having checked Alcatraz on her mooring I left her to it and turned in around midnight.

Next morning I awoke in reasonable warmth, thanks to a significant sleeping bag upgrade earlier in the year, and prized open the tent flap to view a cold but clear dawn – the rain had provided quite a good glazing effect where it had frozen overnight and cracked off the tent in impressive style.

Bay at Barrs

Camp struck, I headed out with Alcatraz to do a little survey of a deepish channel I’d come across a while back, and which seemed to be in range of a modest shore cast. You can see the result from Reefmaster below, combined with a Google Earth overlay – although since it’s miles from the nearest car-accessible spot I’m guessing not many shore anglers will be visiting soon. Having completed this little objective I dropped anchor in the trench and waited to see if anything would show.

Reefmaster and Google Maps chart
Reefmaster and Google Maps chart

A few minutes later the answer came in the form of a series of tiny spurdogs in the 6 to 12 inch range. There were a few whiting as well, some of which were bigger than the spurs they came up with.

Baby spurdogs

Although even these little fellows pack a punch, as I found out when I got spiked by one 🙁

Spiked by a spurdog
Spiked by a spurdog

Even the bigger fish weren’t too much better…

Small spurdog

So it was soon time to head west back along the loch to try another mark.

A beautiful day afloat on Loch Etive

The sun was up and the loch flat calm as I waited it out at another mark half-way down towards Bonawe, so I sipped a coffee and watched the world pass by – rather slowly in the shape of flotilla of sea kayaks.

Sea kayaks on Loch Etive

A pair of sea kayakers on Etive

A few fish did show up, including this beautifully olive-gold coloured little codling and a decent number of small spurdogs (no absolutely tiny ones here, thankfully).

Golden coloured codling from Loch Etive

Small golden coloured cod

Pretty little thing - poorcod head and shoulders
Pretty little thing in closeup – poorcod head and shoulders shot

A final move down below Bonawe produced nothing apart from small dogfish, so I called a halt slightly earlier than planned to allow an early retrieval whilst it was still daylight.

An angry spurdog
An angry spurdog lets fly
Parasitic worms on an Etive whiting
Parasitic worms on an Etive whiting
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Creating your own Personalised Charts

My earlier post on creating personal charts using UKHO data highlighted the amount of freely available, detailed, survey information available.

I’ve now updated and renamed my old DrDepth page to include a more detailed “how to” guide to using ReefMaster software to create personalised charts for use in Lowrance and similar kit.

The topic may seem a little technical but there is some very useful information out there without working up too much of a sweat (just browsing the UKHO imagery will show features that do not stand out on Navionics or C-Map charts).

A series of large sandbanks show clearly in Reefmaster, but are unrecognisable in many other electronic charts
A series of large sandbanks show clearly in Reefmaster, but are unrecognisable in many other electronic charts
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Charting Scotland

Anyone fishing the areas around Mull and the sea lochs such as Etive, Sunart and Linnhe will be aware of the limitations of both the paper and electronic charts for the area, as most are based on very limited and old survey data. Widely spaced soundings can make it difficult to visualise the landscape underwater, particularly in unfamiliar territory, and dropping the anchor becomes uncomfortably close to guess-work.

For the last 6 or 7 years I’ve collected my own seabed data using sonar/GPS logs and running these through DrDepth software to create detailed mini-charts. Admittedly part of the reason for doing this is simply that I like maps, whether land or sea based, and I get a kick out of creating my own. However I have found the insight I get to be very useful in areas I fish regularly and I’ve built up a good picture of Loch Etive in particular.

Chart of part of Loch Etive, generated by DrDepth from Lowrance Sonar logs
Chart of part of Loch Etive, generated by DrDepth from Lowrance Sonar logs

More open water, such as the North Sea, is more difficult to map accurately as wave motion and tidal variations mean that a lot of the detail is lost – it’s still useful, but you are best to survey a small but complete area at a time rather than merge results from different days, and also stick to calm conditions.

Very handily however, a number of recent surveys have been commissioned by the UK Hydrographic Office and the data from these is freely accessible. First off you can get an overview of what’s available here (it looks good, but you can only zoom so far), and secondly you can download the actual survey data itself and run it through charting software such as DrDepth or Reefmaster.

UKHO Inspire Portal Homepage
UKHO Inspire Portal Homepage

Even the overview can quite clearly show wrecks sitting on the bottom, particularly in areas of sandy bottom such as between Fraserburgh and Aberdeen. The example below shows a small part of a large reef system several miles off Dunbar (with a wreck thrown in for good measure). These are serious lumps of rock, with scours at their base and near vertical walls rising 50-70 feet in places, but relatively few anglers know they are there and they’ve only recently started to appear on charts.

A small scale overview of large reefs in the Firth of Forth
A small scale overview of large reefs in the Firth of Forth

To take another example, if you look at the Isle of Mull you’ll see almost the entire island has been re-surveyed in great detail and there is a lot of interesting information available that simply doesn’t appear on a chart.

An overview of the Torran Rocks, Isle of Mull, taken from the UKHO Inspire Portal
An overview of the Torran Rocks, Isle of Mull, taken from the UKHO Inspire Portal

It is hard work, but if you can take it to the next level and download, convert and process the survey data through DrDepth or Reefmaster then you get into a different league in terms of what you can get out. The blurry dot that represents the Halland in the image above can be transformed into a detailed view like that below, where the length, orientation, height of the wreck and a small scour to the south are all clearly visible.

A chart of the Halland wreck, using UKHO survey data
A chart of the Halland wreck, using UKHO survey data

From there it is a relatively small step to generate a “proper” electronic chart that can be loaded in your chart plotter like a Navionics or CMap cartridge – but one that contains much more of the detail you need to see as an angler.

Compared to logging your own data from a sonar log, the UKHO offers much more information and it is also high quality (mostly on a 2 x 2m grid and properly adjusted for wave height, tides, etc,). In a good year I might log 50,000-100,000 data points from the sonar, but UKHO are offering something like 40 million for the area around Mull alone. All available for free download…

This sort of data is somewhat difficult to work with on account on the sheer number of survey points and it’s use of Cartesian positions rather than Lat/Long,  but can give a completely new view of areas that conventional charts don’t really display properly. I’m still working through some of the issues myself, but will be updating my charting/DrDepth pages over the next few months.

As an aside it’s worth noting that DrDepth is no longer available for purchase since being bought out by one of the major sonar manufacturers. I’ve been looking at Reefmaster software as a possible replacement, but there are also other solutions such as Insight Genesis (Lowrance). Reefmaster can definitely handle the UKHO datasets, once converted to LatLong formats, but I’m not sure about other software.

p.s. your mileage may vary – survey data available depends on the UKHO’s work programme. I’m lucky because many of the areas I’m interested in have been recently worked over so there is quite a bit of information for my patches.

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Aug/Sept 2011 – Dunbar

A couple of poor trips out of Dunbar at the end of August/early September – next to nothing apart from a few decent pollack and a small sprinkling of ling and codling (but mackerel in plague proportions).

First trip since early July was very poor – a handful of decent pollack, best over 7lbs, but nothing on the cod front. The drift was almost non-existent most of the day which didn’t help any. Dunbar can be pretty hard at times, but there was a complete lack of codling which was very disappointing. Most of the fish came from well to the east, around the Sicar Point area.

Next trip I spent a couple of hours inshore and on the River Garry wreck but had nothing but mackerel Decent drift and water clarity so no excuses other than a lack of fish on the ground.

Given it was looking like a repeat of the previous Thursday I thought I’d push offshore a few miles to a series of large ridges in deep water – think a collection of Sicar sized ridges fairly close together. I’ve tried here a few times over the years with mixed (mainly poor) results, but it didn’t look like there was much to lose.

The drift out here was fairly fast, at 1.5-1.8 mph and I’d to use 12oz of lead to get through wall to wall mackerel and actually reach the bottom about half the time. Apart from mackerel there was very little – a few small codling and ling, plus a couple of whiting when I anchored up for while. I’d hoped for a larger ling (or something more exotic) on a large fish bait, but nothing doing.

This is one of the areas I fancy for porbeagle, given the size and extent of the ridges and huge numbers of mackerel. I hadn’t planned to fish out here so I didn’t have any heavy gear with me, but I reckon it’s worth a shot on a smaller tide. The pic below gives a flavour of the area, courtesy of DrDepth – most of the ridges have a steady slope on their south side, with a vertical drop on the north. For comparison you can see a large wreck (the Halland) lying NNE/SSW at the SE corner of the image.

a series of large ridges a few miles offshore from Dunbar
The Peaks
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11th September 2009 – Dunbar

Weather:Light NW wind, dry and largely sunny – clouding over later
Sea Conditions: Calm
Time Spent: 10:30 – 17:30 – 7 hours
Tides: 11:58 GMT 1.6m

A DrDepth view of the Halland wreck

Another disappointing day, although slightly better than yesterday. Spent a fair while on the River Garry but fish were just trickling aboard, so I headed over to the Redfish reef and had a couple of drifts getting bugger all. Next, a shift over to the Halland, which I spent quite a while mapping with DrDepth, using separate E run and W run recordings, to try and iron out latency and cone angle effects. Fishing it was a waste of time however, and it was back in to the River Garry for a few more drifts before packing in.

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