Well, regarding the external antennae vs. internal, I'm actually not sure if I'll have the wifi only version or not. I haven't actually received the iPad yet but all I need to do is pick it up.
That's a really good point about the sun and the screen being unreadable in direct light. I will mostly have my bimini up for shade for the baby, although I DO prefer it down
I figure it's worth a shot for the very minimal investment it would be. I think the app is only $35 or $40 and then the $100 for the antennae.
That seasucker mount looks really nice, sounds impressive, I'll look into that more as well.
As a side note, I also have a Garmin Oregon handheld with the Bizer charts loaded onto it, which is what I've always used in the past, and although it does work really well, it is a very small screen and better for hiking/motorcycling than it is for boating. I certainly don't NEED the iPad, more of a cheap toy than anything
Gslpro,
It's a good point about not completely relying on the GPS. I would never 100% trust any single system for nav.