I moved from the Jones Inlet Marina to Al Grover's High & Dry at the end of last season as did quite a few other boaters due to a change in marina mgmt and stricter rules. The new mgmt alienated most of the boaters so we left. I don't recommend them but the JI marina probably has a lot of open slips. You can try Al Grover's who I definitely recommend but I think he is full. Both on in Freeport off So.Main Street.
Forgot to mention:
if you have access to a computer and the web, go to Yahoo, Maps and put in Freeport,NY and get the map. Then click on "nearby business" and select "marina" for your search and you'll get a list of most of the marinas in the area. You can also extend the area by increasing the number of miles from Freeport. Then you start making calls.