Is it worth tacking upwind with a Flat Earth sail?

Flat Earth kayak sails will sail to about 68 degrees off the wind. This means they can definitely get to windward but is it worth tacking upwind or should you just drop the sail and paddle? To find out I did the following experiment and recorded the data on my Garmin GPS.

This GPS track shows tacking upwind into a 12kt WSW wind. Although I seemed to be sailing about 45 degrees off the wind, that was the effect of the apparent wind, the combination of true wind and the wind generated by boat speed. The GPS track shows that a Flat Earth sail will point about 68 degrees off the wind. This compares with about 45 degrees for a typical dinghy with a centre board. At first I tacked upwind while both paddling and sailing. I covered 1600m over the ground but only 600m upwind in 15.28mins. The over ground speed was 6.3km/hr but the upwind speed was only 2.4km.

Next I dropped the sail and paddled directly upwind. I covered the next 600m in 6.72mins, which meant the upwind speed was 5.4km/hr. The conclusion is that it is not worth tacking upwind with a Flat Earth sail. However, if you can lay, or nearly lay your mark, by sailing on one tack then it is definitely worth paddle sailing upwind with the Flat Earth sail. That is exactly what we did in the top photo, we were just able to lay Gull Point at the South end of Little Cumbrae on our way from Portencross to Glencallum Bay on Bute.

Adobe Lightroom 4 review

Being a photo blogger, I often get asked if my photos are "Photoshopped". Well, when I started digital photography I did use Photoshop on a Windows PC. However, when I got a DSLR that produced RAW files, I found I ended up doubling my file storage, as I would have the original RAW file and an equally large edited .psd file from Photoshop. Also Photoshop is not good at cataloguing or viewing files and I never really got along with the Adobe Bridge file manager viewer that works with Photoshop. So I moved to Lightroom 2 as it is a file manager, viewer editor and printer; all in one. As you edit a RAW file, it just saves a small "recipe" of your changes alongside the RAW file so is much more efficient in terms of file storage space. It is also very fast at browsing files and finding catalogued files.

People also ask if I need to heavily edit the photo files you see on this site. The answer is no and I find that Lightroom has more than enough tools to do the job. So I happily upgraded to Lightroom 3, when it came out.

Mostly I just straighten the horizon, sometimes I crop into 16:9 widescreen format like here, to cut out excess sky and sea from landscapes. Also, I use an HD projector at my sea kayaking talks and it uses 1920x1080 pixels. When I am exporting resized photos for the web or slide shows, Lightroom is very good because it will allow batch resizing to the longest edge, if you want portrait and landscape shots to be the same area, or to a fixed edge e.g. vertical edge. This is great if I am preparing a mixed group of landscapes and portrait shots for projection, I will just resize them all to 1080 pixels on the vertical edge to get best results.

Lightroom also has a built in database of the common faults (eg vignetting, barrel/pin cushion distortion) of a wide range of lenses. It has a tool that when ticked will automatically "correct" a photo using the lens data in the EXIF header. I use this a lot with my Canon L lenses.

Other edits I do will usually involve exposure corrections. Either the overall exposure or more commonly recovering detail in the shadows and highlights. Lastly, in landscapes, especially if in blueish hazy conditions, I will sometimes either boost the clarity control or reduce the blue luminance to improve distant detail.

Lightroom 4 has just been released and I am pleased to say that in addition to a price cut, the RAW conversion engine has been updated and the editing controls for shadow and highlight are now more intuitive to use and certainly on the few comparisons I have made with Lightroom 3, the algorithm used seems to produce better results. These are probably the two most useful tools in Lightroom and I am pleased to see improvement. Lightroom 4 allows you to choose whether to convert any of your previously edited Lightroom 3 work to the new RAW conversion engine. You can still work with the old version and tools in Lightroom 4 but if you convert to the new expect to have to make some adjustments.

A major reason I upgraded to Lightroom 4 was the inclusion of reverse geo-tagging. Most of my cameras don't have a built in GPS and the one that does takes so long to get a fix that I have generally taken the photo and switched the camera off before it knows where it is. Previous versions of Lightroom have been unable to import my navigation GPS's gpx file and to tag the photo files with their position in the files' EXIF metadata. I used a separate program called GPicSync to do this but that freeware program took ages to open all the RAW files, so I only used it with small .jpg files I had exported.

Now Lightroom 4 has an extra map screen which allows you to import your GPS unit's .gpx file and very quickly autotag all (or selected) photos with their position. You do need to ensure that the camera is set to the right time so that it is correctly synchronised with the GPS unit's time (which the GPS will get from the satellites). If you forget to do this there is a handy time zone offset slider that will also allow you to compensate if your camera is a few minutes late or fast. This is a great addition to Lightroom, which has speeded my workflow.

All in all, Lightroom 4 has some welcome major improvements, which have made it a worthwhile upgrade for me. If you are not using Lightroom and are still using Photoshop or similar, then do yourself a favour, get yourself a copy of Lightroom 4 now! It is a really excellent program that will greatly enhance your workflow, when you get back from a photo shoot. You will end up with more time to compose and take photos rather than fiddling with them afterwards!

Lightroom 4 is available for Windows PCs and Macs for £103.88 (Upgrade £59.09) free trial available.

Note for Mac users.
Since 1984, I have been ambidextrous, using primarily PCs for home use but using both PCs and Macs at work. Before I retired, I was able to compare Lightroom 3 and Aperture on a well specified Mac Pro (with a Quad-Core processor) using my Canon 5D mk2 RAW files. I found Lightroom 3 to be faster at file handling and previewing and it also has a much more powerful set of editing tools. Lightroom and Aperture use different RAW conversion engines. On my Canon files, the Lightroom converted RAW files look a littler flatter and more natural than the Aperture converted files that look brighter and more contrasty. Some people prefer one over the other. Both programs allow you to adjust the end result anyway but I found that the Lightroom tools work better on my photos. (I found Aperture was less easy to tone down, than Lightroom was to brighten up.)

Given Lightroom's range of effective tools, I think Aperture users would end up using Photoshop much more than Mac Lightroom users. (I hardly use Photoshop since I started using Lightroom.) Aperture also handles the files a different way, wrapping everything into a single database file. Aperture maintains a separate catalogue from the files. I guess that most people brought up on Macs would prefer the Aperture approach but ambidextrous and recent PC converts to Mac probably prefer the greater file control of Lightroom and might not like committing all their photos to a single large file on a (mortal) hard disk's allocation mapping table. (I am still smarting from how little control I have over photo handling in my iPad2, so perhaps I have a slightly jaundiced view of this.) Making the right choice, first time, is important because after you have used one or the other program for any length of time, you will have a lot of cataloguing and editing that you will not be able to transfer. It's a bit like camera systems, once you have bought into Canon or Nikon...

Anyway I recommend that Mac users should also try Lightroom 4 for themselves, it is a great program and it is available as a free trial download for Macs.

A matter of maps and rutters.

The Nicolay rutter was the first accurate chart and pilot for the Scottish coastline. (The word rutter comes from the French routier.) It was unsurpassed for accuracy for several hundred years. Those of you who know the Solway might question the island off Burrow Head to the east of the Mull of Galloway.



It is of course the Isle of Whithorn. Despite its name this is no longer an isle, but it was when the map was drawn. Even in the 18th century, there was still a channel at high tide and a smugglers' boat escaped the Excise cutter by sailing into the harbour and escaping through the channel while the cutter blocked the harbour entrance.

The rutter was created following an anticlockwise voyage round Scotland by King James V in 1540. The original manuscript was made by Alexander Lyndsay. It was made into a printed version in 1583 by Nicolas de Nicolay, a French map-maker. The National Library of Scotland has placed a digital copy on their website which can be zoomed to allow examination in detail.Only a few copies of the map survive and the BBC news reported that one is due to be auctioned on January 10th. I love looking at old maps and have a fair collection having inherited many old linen backed Ordnance Survey maps of Scotland (some from Victorian times) from by Grandfather. As the rutter is expected to fetch in excess of £20,000, I have decided not to place a bid on this occasion.

In addition to many paper maps and nautical charts I also have digital Ordnance Survey maps at 1:50,000 from Anquet maps. I bought all the 1:50,000 maps in the north half of Britain for £100. These can be viewed on the computer or dowloaded to a PocketPC. Unfortunately they can not be loaded into my Garmin mapping GPS unit but tracks from the GPS can be downloaded onto the computer and waypoints created in Anquet can be uploaded to the GPS. However, it is great for trip planning to be able to scroll seamlessly round the coast. You can print the map at the original size on A4 paper or you can zoom out to cram more coast onto your A4 or zoom in to make the area covered smaller but easier to read for older paddlers who do not wish to wear their reading specs.



Sometimes I laminate two maps back to back, sometimes I just keep them in the excellent Ortlieb map case.



For the Garmin GPSmap76cs I have two Bluechart regions:2EU006R and 2EUoo4R. These cost about £120 each. They cover from Corsewall Point to Spurn Head. As you zoom in on these you get more detail appearing as the product includes both large scale and small scale charts. They show the coast line in reasonable detail but very little on land. They are useful for showing water depth which can be a predictor for such things as turbulence in tidal channels. They also allow you to calculate tide times for a large number of ports. This works both on the computer and the GPS. Both Bluechart regions fit comfortably within the 115MB memory of the GPS.



For the Garmin GPSmap76cs to show contours on land and also more detail between HW and LW than the Bluecharts, I bought the Garmin Topo map of Scotland England and Wales for £130. This is based on the ordnance survey but has less detail of woodland, buildings etc but it does show roads. You cannot print from it and on the computer the size of the detailed screen is restricted. On the GPS unit it is very clear and is good for locating skerries, beaches and burns. The maps are large files so you have space to load only those of the general area you are heading for into the GPS, the whole country will not fit.



With regard to online maps, I like to use Streetmap in this blog to show the location of photos. It allows me to enter a grid reference from a paper map or Anquet computer map. Pasting the location url into a link in the blog allows readers to open the streetmap page then zoom and scroll.

Another good online "map" is Google Earth. This can even import GPS tracks. Once I have the Google Earth window on the computer screen I save the screen to memory. (On a PC: SHIFT+Prt Scr)



Not all of Scotland has such good photos as this but for those areas with good coverage Google Earth can allow you to explore for campsites and can even show shallows.

It would appear that an advantage of being invaded by the USA is that Google Earth resolution dramatically increases. Ultimately, military use is what has driven the development of maps and also GPS. The British Ordnance Survey had its roots in the Jacobite Rebellion of 1745. In 1746, after the defeat of the Jacobites at Culloden, King George II of Great Britain commissioned William Roy to survey the Scottish Highlands for military purposes. Roy's name is engraved on the door of the Ordnance Survey headquarters in Southampton. Two centuries earlier, James V of Scotland commissioned his rutter to help quell the troublesome Lords of the Isles. The map was so strategic that it was obtained by the English who commissioned Nicolay to make printed copies; one of which was obtained by the French. They used it almost immediately to avenge the murder of Cardinal David Beaton of St Andrews who had been murdered during the Scottish Reformation.

What would Lindsay have made of Google Earth?

On 9/1/2008 Mark added:

"There is another way to get contour information onto a GPS without buying the TOPO maps. The necessary files, Contours v2, can be downloaded for free from the SMC website. You still need the Garmin software to get them on to the GPS itself but they are a big improvement on the Garmin base map.

It seems to work as a sort of overlay on the base map. This leads to some oddities such as sets of contours appearing where the base map shows sea but as the contours tend to be more accurate I have found that helpful as a kayaker!

They were put together by Dave Storey who must have spent a lot of time on it.

Not sure if I can post links here but I will try. The files are at http://www.smc.org.uk/ContourMaps.htm and there is a very helpful set of instructions at http://www.paulmac.force9.co.uk/geo/index.html.

Mark"

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!