I visited Desolation Sound this year in March and April (2010) to test out using Opencpn-136 and cm93 charts.
I installed the free opencpn software
from Cruisers Forum onto my laptop
computer and then bought Microsoft's "streets and maps" software
that comes with a GPS
that connects to the computer. I didn't install the streets and maps software but used that GPS
with the opencpn software instead. It works great. I downloaded the cm93 charts from the internet.
We went from Anacortes Washington
to Desolation Sound with stops in the Gulf Islands, then accross the Strait of Georgia
through Welcome Pass into Pender Harbour then up Malaspina Strait with a stop in Powell River then on to Desolation Sound.
The cm93 charts were GPS spot on everywhere I went with the exception of the entrance to Prideau Haven that was a little off. I always say that I can get to the outer marker, I'll figure a way to get in the place. After we were inside Prideau haven the CM93 charts were GPS spot on again.
Now we must remember that the goofy US Governments GPS signal is dithered every so often and this might be why it was not giving us the proper location when were at Prideau Haven's outer marker.
Example, when we continued on through Desolation Sound we noticed when we entered another inlet the GPS was spot on but when we went to turn around and leave just a few minutes later it showed we were 50 meters inland, but a few minutes later the GPS signal was again spot on according to the cm93 charts.
CM93 charts are world wide for big ship navigation
and if you want to check them out you'll see that a little spot in the South Pacific
turns out to be Tahiti
with the whole reef with inlets and buoys.
The free opencpn software is amazing and I really want to thank those who volunteered to build it, so try it, you'll like it.
Fair winds, and following seas,