Saturday, December 02, 2006

Subterranean echoes of dripping water.



As I paddled alone deep inside the cave, the sounds of the outside world gradually diminished. There was only the gentlest of swell and it hardly disturbed the calm at the back of the cave. After some moments my ears and eyes gradually adjusted to the noises and colours in the cave. There was the most wonderful sound of water dripping from the darkness of the cave roof into the sea beside me. The drips echoed round walls of iridescent reds and greens above a turquoise sea.



This is sea kayaking

Friday, December 01, 2006

Easdale buoys, fools and slates.



We took the Aleut Sea II out to the small island of Easdale that lies off the west coast of Argyll's Island of Seil. We landed on a beach of dark grey slates.



These buoys adorned a building of slate.



Climbing to the top of the island, we saw the great flooded slate quarries that have hollowed out this island's heart. The photo shows the breaches in the quarry wall that a tidal wave made during the great storm of 1881. At low tide the walls are still complete and locals try and catch the fish that have been trapped inside. The quarries go down to 80m below sea level. At their peak of production, in the 1860s, Easdale slates were exported to, Australia, New Zealand, the Caribbean, the United States, Nova Scotia, Newfoundland and Labrador.



Easdale slate is very fine grained but it contains little cubes of iron pyrites or "fool's gold". If you break the slate open the crystals shine brightly but they soon rust when exposed to the air. If you live in one of the above countries and you come across a building with a slate roof have a look and see if the slates came from the little island of Easdale.

After the collapse of their industry, the miners and their families followed their slates to Australia, New Zealand........ They carried the names of their families and villages with them.

Thursday, November 30, 2006

Cuan Sound.



One of the most fun things to do in a sea kayak is to play in a nice tidal race. Between the islands of Seil and Luing lies the narrow Cuan Sound.



The flood tide is compressed as it travels up the great Sound of Jura and through Shuna Sound until it squirts out through the Cuan sound at up to 15km/hour.



As the tide turns the flow reverses and unlike the tide in more open waters it reaches maximum speed very shortly after turning.



In a recent post about wind farms Iona commented that tidal power is efficient and less intrusive. The Cuan Sound is one of the sites under consideration for a tidal barrage or fence to generate electricity.

We enjoy the Cuan Sound while it is still a free ride through!

Wednesday, November 29, 2006

Psalm 59 on Scarp



In a recent post I mentioned the remote island of Scarp off the west coast of Harris in the Outer Hebrides. After the failure of rocket mail its inhabitants were finally connected to the mainland by submarine telephone in 1947. It was destroyed by a storm in 1970 and the GPO refused to replace it. The islanders finally evacuated Scarp in 1971. By tradition they had left a Bible in each house. By the summer of 2006 the houses were in a sorry state after 35 years of winter storms. In one house pages of a bible had blown about the windowless room.



Some days later we met the gentlemen in the centre of the photograph on Canna in the Inner Hebrides. It turned out he had grown up on Scarp until his family emigrated to Glasgow. We had a book about Scarp Hebridean Island, Memories of Scarp. He was able to identify many of the individuals in old photographs reproduced in the book.

Tuesday, November 28, 2006

Courses, bearings and GPSs



Most sea kayak navigation is done by identifying coastal features, checking on the map where you are in relation to them then paddling towards the one you want to get to. However, fog, night or tide might make things more difficult. I used to be a Luddite when it came to GPS units and it is fair to say that although I am a technophile, I was a late GPS adopter.



In this case I want to paddle to the channel to the south of Pabbay Beag from Stacanan Neideaclibh. The horizon is pretty featureless so I can take a grid bearing off the map, convert it to a magnetic bearing and the course is 89 degrees between the two points. I now paddle on a heading of 89 degrees and I should get there. But if there is a tide carrying me north from the course line, my bearing to my destination will change to say 92 degrees. I will have no way of knowing this unless I have calculated the speed and direction of the current before hand or if I have identified a more distant landmark behind my destination and the two move relative to one another (this is called using a transit). In this case there is no suitable transit landmarks.

This is where a GPS comes in. I set a waypoint in its memory for the place I want to get to by either; 1. entering a grid reference, 2. on a mapping GPS scrolling the pointer to the map position then pressing the MARK key or 3. if I was there earlier in the day, by pressing the MARK key when I was in the middle of the channel.

Next I press the FIND key and select the waypoint. The GPS then calculates the distance and course from your start location. Most GPS units have a GOTO page which displays a large arrow which points on a compass rose to the bearing from your current location to your destination. If you drift off course then the bearing changes. On simple GPS units the bearing pointer points to the top of the screen if you are on course. On more sophisticated units the bearing pointer will point to the destination if it is held flat. This is all pretty complicated to describe and in practice in rough water and if your eyesight is not very good, you will end up a long way off course before you detect the change in the bearing arrow.
In practice it is easier to monitor any change in the bearing as a number. On my Garmin GPSMap76cs I can set the bearing to the destination on a large type screen as a number. This is very easy to see especially for those elder paddlers whose close up vision is no longer what it was. If the tide carries me off course to the north, the bearing might Increase to 92 degrees. I now paddle more to the rIght and the bearing comes back to the course of 89 degrees. If I was carried off course to the south, the bearing might dEcrease to 86 degrees. I now paddle more to the lEft and the bearing comes back to the course of 89 degrees. In practice it is easy to keep within about one degree of the course on typical sea kayaking distances.

The GPS allows you to maintain a perfect ferry angle despite changing tidal flows. This is a function that map, compass, tide tables, chart and your brain would be unable to match. Off course it needs to be used sensibly. If you are crossing a channel and expect to be half way across at the turn of the tide, you may as well paddle straight across on a constant bearing and allow yourself to be carried down tide then up tide and these will cancel each other out and you will not waste time ferrying into the tide. Another point is that GPS units can be set to use various Norths such as grid and magnetic. I always set mine to magnetic so that if the GPS fails I can just switch straight back to the compass.

I explained all this to a friend who is very keen on skin on frame kayaks and Greenland paddles. He was rather dismissive of all this technology and wondered what was wrong with a good old compass. However, I am pretty sure the Inuit did not have compasses (not to mention aluminium frames and polymer skins).

PS in response to Cailean's reply.

In May I was fortunate enough to be part of a group that was led out to the Ecrehouse reef which lies 10 km off Jersey in the path of tidal currents that run up to 5 knots.


The leader was a very experienced local paddler who had been out to the reef countless times. He used local knowledge, his experience, compass, map, tide tables and tidal flow charts to take us out by the southerly route above. It was a safe crossing and allowed us to get carried down onto the Ecrehouse. If we had missed it we would have ended up going to England. However, we battled for 2 km more than we had to into a 3.5-5 knot current which was extremely tiring and a couple of paddlers in the group were very nearly exhausted by the crossing. The leader knew I had a GPS and asked how we were doing at the point we changed direction.

If we had done this crossing using the GPS then I would have set a waypoint about 1 km up tide of the Ecrehouse (at our final change of direction on the chart above) and we would have paddled straight to it.

I do think that being able to ferry at just the right angle using a GPS can conserve a groups' energy to leave a reserve for any unexpected tide or wind conditions they might meet later.
Here is a GPS track of a trip to Ghigha. On the way out it was flat calm and slack water. On the way back there was a 2 knot north flowing tide and a force 6 southerly wind. I used the GPS track not to navigate such a short crossing but to adjust the ferry angle. As you can see it was an efficient crossing in somewhat lively conditions!

Monday, November 27, 2006

Photography, is Photoshop a cheat?



This is a nice photo of a summer sunset off Loch Roag in Lewis. It is very much as I remember it but it is actually composed of 2 separate photos which were taken one after the other but with very different exposure settings. One was taken for the light in the foreground and the other was taken for the sunset. I joined them together later using Photoshop. If I had just set the camera to auto, the kayaker would have been a dark silhouette.

Simon Willis has recorded a Podcast with me talking about sea kayaking photography which should be published in the first week of December. The above photo is one that will appear on his website to accompany and illustrate the Podcast.

Some photographers do not like this type of photo, saying they look unnatural. What they really mean is they don't look like the photos they take! The human eye copes with a much greater range of light as it roves round a scene (with the iris altering its aperture as it goes) than a camera which takes a fixed exposure for the whole scene. Film and digital senors are also much less sensitive than the retina. Whatever, I like the technique and it's really just a development of dodging and burning when exposing a print in the darkroom. I did a lot of B+W photography before moving into transparencies but many photographers missed out the darkroom and have spent most of their careers using transparency film which allows for no post exposure manipulation. It was a highly skilled job getting the correct exposure on good old Kodachrome II transparency film with its 25 ASA speed and narrow exposure latitude. Those photographers take a great pride in getting exposure right first time and Photoshop must seem like the spawn of the Devil to them.

I think you can take photography far too seriously. As I said in the podcast to Simon, I am not a forensic photographer recording a crime scene. I am just trying to capture memories and memory is a fleeting and fickle thing.

Sunday, November 26, 2006