Garrison Bight marina.
We just went down to Key West and stayed here before departure on sunday and on return on thursday. You have to leave your mast down or lower it to go under one(or 2 bridges depending on your exit strategy). I think it was $26 per night, $6 ramp fee, and $6 per day for long term parking. There are no frill showers(deposit for the key), security guard, and pets were not a problem. Sorry I don't have the number but of course you need reservations. There was even a manitee at the dock.
