Re: [Amel] Chartplotters, upgrading electronics


dlm48@...
 

Interesting since are you the oldest old salt here i come from a time of RDF (an electronic aid to make sure you were really lost) and 'perhaps' if rich enough Decca and yes a lead line too.

Sadly people now 'KNOW' or think they know where they are - at least in the old days i knew where i was not and was always constantly looking for signs to tell me where i was.

The only real help i had of course was a paper chart which may not have been accurate to the nth degree especially in the way of its position in a GPS mapped world - but in relation to the dangerous 'bits' was the help i was seeking. For sure it was considered gospel and only needed updating when things changed under the influence of man.

I know of at least one boat that hit a very famous rock in Scotland because it was not on his electronic chart - things are too easy now pre staring a passage we dont sit down and pore over a chart and plot in a few possible courses pencil in tidal streams work out high and low water times and highlight dangers.

Its a click click process now switch on the plotter and gosh there is our boat exactly where we expect it to be - tidal heights are shown phases of the moon, date and time, air temperature, water temperature, wind speed and direction, boat speed, speed over the ground, course/heading, and course over the ground, depth, the number of fish hiding beneath the boat, and of course most importantly whether it is your Mothers birthday - so we are 'minded' to believe this electronic box 100% forgetting that is us that have the brains and it is us that must evaluate the risks and look for and list the 'possible' dangers on the passage.

On a long passage i am sure reading a book is much more fun - unless of course you have missed your mothers birthday that would be very worrying. And yes i maybe the ancient mariner but she is even older (somewhat unsurprisingly)

regards

David

-----Original Message-----
From: John and Anne Hollamby <annejohn@melita.net.mt>
To: amelyachtowners@yahoogroups.com
Sent: Tue, 20 Jan 2009 2:54 pm
Subject: [Amel] Chartplotters, upgrading electronics






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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