Let me ask the more fundamental question -- why do you want a chart
plotter?
"Budget", "round the world", and "chartplotter" don't go in the same
thought for me.
If you assume you need paper charts for backup, then having a
chartplotter means you need to buy the data twice, once on paper and
once on CD (or whatever). It took us about 350 charts to do our
circumnav. Doubling the bill for these is thousands of dollars. I'd
rather spend the money elsewhere.
Second thought. Many of the charts you will use were surveyed in the
good old days (a new 1995 DMA/NIMA chart has a survey by James Cook in
1783 -- the oldest I've found) and the datums are off. Often this is
a constant error for the whole area (usually, but not always
longitude). If you take some radar or visual bearings as you near an
island, you can establish the actual position of landmarks and figure
out how much to move the lat/lon lines to match reality. This is easy
on paper, but I don't know a chart plotter that will do it. Of course,
doing this does not give you an accurate chart that you mindlessly
trust, but it is convenient.
Third thought. In the progess of your trip, you will change your
plans, perhaps often. It's easy to get paper charts of an area on the
spot, but matching electronic charts can't be found in the boondocks
(we had an 8.5x14 HP flatbed scanner on the boat -- only 3x11x16" --
so we could make limited copies).
Fourth thought. As you go along, you will find that the best charts
of an area are from the chart agency of the nation you're in. For
French Polynesia, you want SHOM charts, which are now available from a
USA dealer. They're far better than the USA or BA coverage. Maybe you
can get SHOM charts for your plotter. Also, probably, New Zealand and
Australia. But Fiji, Thailand, Indonesia, Turkey? I don't think so.
Fifth thought. Sailing all the time in new, poorly charted, waters is
demanding on the navigator. I like very much the discipline of taking
out the paper chart, laying out waypoints in sensible places and
drawing in the course lines. It gives you the chance to really look
to see where you're planning to go, and how near to dangers. Then I
measure each leg, distance and bearing, and mark it on the chart.
Then, when I enter the waypoints in the GPS, the range and bearing in
the GPS had better match the distance and bearing on the paper chart
-- if not, I've made an error. (BTW, many BA charts make this much
easier than any USA charts -- they have a lat/lon scale down the
middle, with decimal minutes, while our large scale charts still use
minutes and seconds).
A chart plotter does all this for you, but you lose the close look at
the whole chart and the whole course line. And, don't forget, the
chart plotter thinks the chart is accurate. You know better, and
sometimes the error is miles.
So, while we certainly will have a chart plotter aboard Fintry, and
will use it in "home" waters -- at least the East Coast of the USA --
when we go off again to strange and wonderful places, it will paper,
and only paper, even though Fintry's budget is, I guess, somewhat
larger than yours.
Jim Woodward
www.mvFintry.com
"Ric" wrote in message ...
Hello,
I am fitting my boat out for a round the world cruise.
Currently I have a raymarine 425 chartplotter. Unfortunately this suffers
from two disadvantages - first it uses proprietary memory chips for the
charts, which means that I would not be able to electronically download
charts from the internet and load them as I need them - and second it is one
of the worst chartplotters for PC connection as Raymarine seem to have
cornered people into buying their own expensive software to connect.
I am therefore after a more user-friendly chartplotter. Basically I would
like to find a chartplotter that firstly takes Compact Flash cards (thus
allowing me to erase and load charts as I move, downloading them from the
internet or sweapping them with other sailors as needed) and which also
allows easy connection to freeware PC programs.
Ideally, is there any chartplotter out there yet which can use indifferently
all the different electronic chart formats out there? That would be cool!