Obtain and review carefully the CC&R's and Rules of the Association as to the prevailing requirements of slip owners; and, as to how such rules and particularly fee assessments could be changed in the future (with or without your agreement). Look also, carefully, at fee assessments and what reserves are. A number of "dockominiums" in Florida are now having difficulty because owners have fallen into arrears of their fee payments and other owner/occupants are having to make up the shortage to ensure the basic services are available--water, electricity, trash disposal etc.
Further, look carefully at restrictions on use, occupancy and leasing. For example you might find that the association has the right to rent your slip to transient boats in your absence (and to keep the rental proceeds). You may also find that cannot lease/rent the slip to another when you are not occupying the slip yourself--such as when you are between boats. Look also for restrictions on things such as working on your boat, which may be prohibited; and/or, restrictions on tradesmen working on the boat for you--mechanics, divers et al--without the prior approval of the Association, Insurance etc. Look also for restrictions on how long you may stay aboard you boat at a time, within a month; and, per annum. Many dockominiums do not want defacto "live aboards" and have restrictions that make doing so impossible. CHeck also for parking and storage allowances. Taking a 5 day cruise can be difficult if your parking allowance is only 72 hours continuous.
There are other considerations but the foregoing will get you started.
"It is not so much for its beauty that the sea makes a claim upon men's hearts, as for that subtle something, that quality of air, that emanation from the waves, that so wonderfully renews a weary spirit."