1: I live in an RV and Florida campgrounds (family friendly ones at least) are cost prohibitive.
I see you are a USMC vet. If you happen to have retired ( or just have a DOD ID card at all) there is a RV campground in Key west on base (Sigsbee) (reasonable rates). It is a 6 month maximum stay, with 2 weeks of penalty box before being able to park there for another 6 months.
The shore diving is blah in KW, but a drive to KL will open up some shore diving. On the other hand, if you have all your own gear, reef charters are dirt cheap down there.