I have used the Dual gps and love it. I'm also a pilot and it works at 120 mph and my brother-in-law is an American Airlines pilot and it work in the 777 on international flights just fine.
I'm heading off to the Caribbean
starting this next month to the Bahamas
. I have used the SeaNav US for the last year and it has worked well for me on the east coast
It looks like the leading candidate for non US is charts
and use on the iPad is the NavX app which I believe costs $49.99. Are there choices of charts
that can be used with that app or are the Navionics
charts for $54.99. Are they updated without charge and if you get the AIS
is that an additional cost and dose it work without wi-fi?