Tony.
Yes, have been using the Navionics charts to study the Morbihan gulf, I've also bought the admiralty chart which is even more scary!. There appears to be an awful lot of rocks to dodge, somewhat disconcerting for an east coast mud hopper like me.
Re Google Earth and charts - I use
www.visitmyharbour.com quite a lot, which I think is excellent value (£25 for a lifetime subscription to nearly all charts in Europe, I say nearly because it appears that the French won't license them to use their charts!) but they now have a facility to overlay nautical charts on Google Earth, I understand that if you link up your GPS to your computer it will show your position and track directly onto the chart/google earth combination. I've not actually used it yet but I will certainly explore this in the near future.
Good stuff.
Incidentally VisitMyHarbour now also gives tide tables and tidal atlas .. very useful.
Talking of interesting web sites.. Have you (and others) seen Dylan Winters excellent site
www.keepturningleft.co.ukHe is circumnavigating Britain very slowly but exploring virtually every river, creek and estuary en route, as he is a professional cameraman he is making some excellent video clips of his journeys which are on his website, which for a very nominal fee you can subscribe to and download or purchase his DVD's - some excellent sailing porn!
I had the pleasure of meeting him at Gibralter Point a couple of years ago. A very interesting, self effacing man and a true sailor.
Andy