FYI. The latest version of Google Maps on the IOS supports offline maps. I downloaded the Bvi area before I left the states. I used this 3 weeks ago while I was in the BVI. We had a center console and no navigation. I know the waters there and did not rely on it but it did work. This would give you the satellite view of your anchorage.

I was awesome. I thought I had a screen shot but I don't see it.