Ok, I've been concentrating on revising for my Day Skipper (starts Sunday) by re-reading Tom Cunliffe's excellent book and also re-doing the RYA's Navigation Excercises.

Having come to the end, I've just noticed that at no time have I learnt how to use a typical chart-plotter setup.

I have a Garmin GPS550s but with no boat to attach it to yet I haven't been able to try it out.

I also have Imray's excellent app on my GPS i-devices along with a full collection of local onboard charts for it. But I've not tried using it yet with no boat.

Knowing how quickly things move along in this digital age, I suspect that common practice is now very much on the lines of "GPS backed up by paper charts etc." Indeed I just noticed that my nearly new RYA Navigation Excercises is dated 2008.

Anyway, finally, my question is: "can anyone recommend a good online resource that would help me to get familiar with using a chart plotter"?