Tuesday, 23 October 2012

Moving and Navigating

As the dedicated reader may have gathered, the Owners Agent and I are in the process of moving house. And what a process. We know when we are moving, we know where we are going immediately and we know where we want to be in the longer term (not where we're going to be immediately). What we don't know is when we'll be at the end point.

Just to set your mind at rest, we are not moving into Vagabond whilst she is parked in the barn at Kings Ash Farm. (Not ever, I hear the Owners Agent asserting very firmly.)

As a bit of light relief, I have discovered that I have recorded most of the track that Vagabond follwed this summer and that I can display them on a PC. So now you can be amazed by this technology as I publish these tracks over the next few weeks. You can re-live each leg and refer back to the blog of the day!

The "Nav Station"- the scribble on the right is my passage plan of the day.
Firstly, though, a word on the instruments fitted aboard Vagabond. This photo shows the "Nav station" of Vagabond swung into the "under way" position. When at rest, the board can be swung into the cabin. In the middle of the trip (crossing from Holyhead to the Isle of Man to be exact)  I realised that this arrangement was a bit dangerous -  in really rough weather there is a real risk that the cabin could be flooded by a wave coming down the companion way.
I use Navionics software and charts running on my Ipad2 mounted in a waterproof case (the blue rectangle in the photo)  as the main source of navigation information. The Ipad2 includes a GPS and the Navionics software is excellent. There are three snags with this arrangement.

The first is that I have to rely on the internal Ipad battery power whilst it is in the waterproof case and this can be marginal if it's left on all day. I overcome this by making sure the Ipad goes to sleep after 10 minutes of operation (as it is in the photo) but this does mean that you can't record a track as the GPS loses position when the Ipad is asleep.

The second snag is that it is sometimes difficult to see the screen in very bright daylight. I overcome this by having the Ipad mounted on a quick release strap (Velcro!) so that I can take it off the board and put it into a shaded spot to read if necessary (it is tied on too!)

The third snag is that the Ipad does not communicate with any other instrumentation - I daresay you could do it using the wireless interface but that is (a) beyond my competence and (b) would use even more precious amps.

So I have a second GPS, the Garmin 620 already discussed. This serves as a back up to the IPad, as it takes its power from the main batteries and, as I have discovered, records the track.

It talks with the VHF, to give it the GPS details for the dreaded DSC Mayday call, and also listens to the radio information on AIS data from other ships. When the radio identies a potential "target", the GPS displays them and it shouts at you if they are dangerous. Usually this warning is very pessimistic and can be ignored once one has identified the target although it did make me wake up when one of those fast catamaran ferries snuck behind us near Poole.  

As originally fitted, there was a TackTick wind sensor at the mast head, communicating with a Tactick display. This also receives Sog and Cog from the GPS so can show both relative and true wind speed and direction. It's blank in the photo above, showing that the picture was taken after the sensor had been blown off.

Finally, there's a TackTick depth display. On a couple of occasions (when sailing very quickly) is has shown spurious results.

The ship batteries are topped up by a couple of solar panels mounted on the poop. I have not yet exhausted the batteries during a cruise but have only been away from shore power for a couple of days at the most.

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