One further thing you might wish to consider – will you want to integrate AIS with the Chartplotter? I don’t think the C Series will interface with AIS but the E Series will. I’m not certain about this but I’m sure someone will correct me if I’m wrong.
If you cross the Channel, or just want to see the names and destinations etc. of the big boats in the Solent, then AIS is well worth having. It is particularly helpful for collision avoidance – much better than radar as it works from the GPS data on both the target vessel and your boat, not on wildly yawing radar data (even with a gyro stabilised compass) that you get with MARPA. It gives you the name and call sign (so you can call them up if necesary), SOG, COG etc for all the big ships within VHF range – at least 16 miles. It also calculates the CPA (Closest Point of Approach) i.e. is it going to hit me, and also the time to CPA (how long have I got).
The NASA AIS ‘Engine’ that I use only costs around £120 and all you need is another VHF aerial (pushpit mounted is fine).
PS I use a laptop (not a chartplotter) with Maptech (for navigation) and AIS running in a separate programme – see the article I wrote in the Aug06 BOA Mag. With a chartplotter, it’s all integrated in the one picture, I think – perhaps some E Series expert can help us out here?