Re: Sand Hook and South
Andreas, I don't think you're going to find a pool at any NJ marinas, around Sandy Hook/ Raritan bay. The Highlands has plenty of restaurants. You can just cross the bridge to the beach. Most of the Public North Jersey Marinas are pretty rough around the edges.
Great Kills Harbor Staten Island is nice..with several nice restaurants within walking distance. People swim/wade in the bay there.
If you're looking for resort type marinas, you might want to try the Long island sound.
Huntington Bay..West Shore Marina had a nice pool that I enjoyed while waiting for a part to arrive once.