Chartplotters, upgrading electronics


John and Anne Hollamby <annejohn@...>
 

Hello Kent,
As I am probably the oldest old salt on this forum I hope you will forgive me for preaching to the converted! Modern electronics have a few characteristics which need to be borne in mind. One is that many ships and yotties use the fairway buoys as their starting and destination as waypoints and set their autopilots to "track". The problem with this is that this keeps them in a narrow channel thus ensuring that vessels meet each other en route so the prudent yottie will avoid this unnecessary hazard by having safer waypoints.
Electronic charting means that one may change the scale very easily and one has to be aware that hazards may or may not be shown on the small scale that may be set for passage making. For example one might use a very small scale on a long passage so that one can see the destination.
The October Yachting Monthly contains a report about the loss of Asolare,an Amel 54, on Moore Reef, some 52 miles NW of Willis Island on his route from Vanuatu to Cairns whilst he was participating in the World ARC Rally. There were two persons on board and as the Insurance with Pantaenius specified that there should always be three persons insurers used this fact to reject the claim even though that it had no bearing on the disaster. The owner was seventy years old and had some 50 years experience.
It appears that his electronic charts, supplied by Jeppeson in 2007, did not show the reef which was clearly marked on earlier versions of C Map. The report says that as he closed the Australian coast he changed from his passage chart to two coastal charts for the approach to Cairns and he says that the reef was not shown on either chart adding that it was actually on bottom of one and the top of the other. I do not understand this comment as C Map charts are seamless. Perhaps a slow chartplotter would not be seamless when moving from one chart to another? He was also carrying all the relevant paper charts.
I have looked at Moore Reef on my 2002 version of C Map. The reef is at about 15deg55'S and 149deg15E and is not shown on the scale 1/10mllion nor the 1/2.5m scales but is on the 1/1m scale.
The problem with answering your question about which is the best gear is that most of us have only experienced with one system and, I suppose, are happy with it. In my case I have an old laptop, circa 1998,with a 33mhz Celeron processor and a 12"screen, which we got originally to use with a Sat C transceiver. Even this is probably much faster than the processor in most chart plotters and the one in a modern laptop would be infinitely faster. This sits on a non slip mat on the chart table and I suppose that one could have a PC in a locker and have a larger monitor on the top or even on a USB cable up to the cockpit when entering harbour etc. This however does not give you the advantage of an integrated radar display although an AIS engine would show most other large vessels.
We have just flown back from visiting Opua in New Zealand where we met the owner of my last boat, an Oyster 435 who has just installed a small chart plotter above the steering wheel. The screen was so small that I was unable to demonstrate the Moore Reef problem in the time available perhaps because he was unfamiliar with the thing.
Pre GPS one did not know ones exact position for extended periods and nowadays people seem to expect to know where they are 24/7 even though the equipment uses up power.

I hope this helps, best wishes from Anne and John. SM319

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