This may be "old hat" to some - this website (may have to play around with it) will show you GPS/plot charter info on various BVI anchor sites "as if you were there in your boat".
I'm using it for a preview of San Juan Island trip next week (that's Northern Washington State near Canada with 55-65 temps and protected charter waters)
Any way > its free and you can look at anchor sites/water depths.
The apps for Android and iOS have additional features, but you have to pay for yearly subscriptions for the region(s) you use. I just renewed my subscription for the US and Canada. I'm sure I'll subscribe to the Caribbean region if I ever make it back there.
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