The pennenkamp park snorkel/glass bottom boat trips are hard to beat for a non diver. The cost is low and they take you out to one of the shallower reefs and let you stay in the water for about two hours if you like. It was what got me interested in scuba. We took a 7 day vacation to the keys and I was not yet certed. I snorkeled pennekamp on their boat and from shore. Boat is nicer. Even went in off smathers beach in key west. Park was alot nicer. Beach was shallow lots of smaller fish, urchins galore, and water was warm. Off the boat we saw alot of fish, a turtle, and at the end of the time, just before getting back on the boat, someone said shark! ducked under and not 10 ft away a bull about 9ft long went cruising thru the middle of the group. My buddy and I started to follow it as she still had some film left but thought this might not be a good idea. Three months later snorkeled cozumel on a cruise and got back and got my ow cert. If your friend has a good time in the keys with this you may end up getting another dive buddy.