The stern section of HMS Rhone is in shallow water and some parts
are accessible to snorkelers. The main part is in 60-80 ft. But the water is clear enough most days that you can see a lot from the surface.
There are some good places to snorkel in BVI. Over by Jost Van Dyke there are sandy spits with lots of critters and corals. Down in Virgin Gorda sound there are some protected waters worth snorkeling. Most major islands with dive infrastructure have published dive guide books
. A lot of those also have online dive site listings.
When you get to an island that has diving stop in at a local dive shop. They usually have a sketch of the dive sites on the wall. Ask them about the regulations
on diving. Usually they will be happy to tell you what you are allowed to do on your own. Many will rent tanks
to you for a few days. This is much easier and less expensive than trying to build your own compressor
on board. If you have tanks
of your own that are within hydro and VIP dates some shops will fill them but some won't as a matter of policy. They have too much at risk for little reward. Unknown tanks can explode and cause a lot of grief so some shops just have a rule
not to fill private tanks. So don't be offended if they won't fill your 1990 Luxfer 80 cf cylinder.
If you haven't been diving in a while take a refresher course at a shop on some island or south Florida
. If you plan to dive with just your crew at least 2 of the crew should be recently trained in emergency
first aid. The recommendations from 20 years ago about diver rescue
techniques and CPR have changed a lot in recent years.