I am a new owner (H 376) but have sailed frquently in the BVI's. This year, aboard my friends 40 footer, I used the Navionics application on my iPhone, which includes detailed maps of the carribean. Granted it doesn't do everything like getting coffee heating in the galley ( there's an app idea!) but it provides so much detail, even at remote places like Anegada, showing the depths and critical channel markers. As a vacationer , I found it convenient to click on a hotel "marker" and get details - phone number, VHF frequency, and occaisionally even more detailed info. When tested alongside the GPS on the binnacle, it was spot on for location, track, and all other parameters. It also has convenience options, like allowing photographs to be taken from within the app, and geo-tagging them. It will even allow immediate upload of photos to Facebook, if you are logging your travels for your friends. I know that some "purists" won't appreciate this option much, but it's a great way to let those land-lubbers in on the fun. Wish I were back there now. My boat is drydocked until spring.