You can get the NOAA ENC files for free, as well as a viewer. See:
http://chartmaker.ncd.noaa.gov/
Don't know if they'll do what you want, but the price is right.

"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!