AFAIK, there aren't any marinas on Pine Island that can handle your boat. You'll probably end up at Cape Coral
or Ft. Myers Beach, which is a ways from the north end of Pine Island, but closer to your friends in Ft. Myers & Bonita Springs.
The most obvious choice in Cape Coral
is Tarpon Point Marina. The Sanibel Causeway bridge is 70', so not a problem. Tarpon Point from the river is narrow, stay in the channel and you'll be fine depth
Ft. Myers Beach north of the bridge is Moss Marine
, I'm not sure Diversified Marine
has transient slips. The bridge is 65', you can go under with no problem at a lower tide (+0.5 or less), I do it with a 65' + antenna
, etc. all the time. Once under the bridge you have options of mooring
balls or a couple of marinas, Mantanzas Inn, Salty Sams, or Snook Bight Marina.
The are good places to anchor towards the north end of Pine Island, Useppa, Pelican Bay, etc. The marina on Useppa is a private club, I don't think you can get a slip there. I'm not sure whether Cabbage Key Marina has overnight transient slips or not. Otherwise it's Gasparilla or Burnt Store Marina.