Re: BVI chart/nav app
To be very straight on this topic:
The BVI is maybe the easiest (by far) place to sail. Anywhere in the US is far more challenging. Maybe, just maybe, the Adriadic side of Greece "might" be easier, but it is close. Certainly a sailors paradise. Really don't fret, simply enjoy and explore. Line of sight is standard nav method here. Someone very high up had sailors in mind when the BVI was created. And the good natured BVI government had the initiative to improved upon that. Hard to go wrong here. Anegada is slightly challenging but any overnight sail, say in the Puget Sound, is far more difficult.
For God's sake, they even put 6 foot painters on all their mooring balls rather than the idiotic 2 inch diameter eye standard on all PNW balls. The Moore Secure company even tests/inspects each mooring ball every year in the BVI, yes, they do that. In the PNW I would never stay on a ball above 20kts.
Enjoy, and don't fret. Too often too many people over think their adventure in the BVI. It is brain dead simple. I wish someone told me that on my first trip there long ago.