Visit Sandy Hook ...
and there are several places to drop into along the way. For instance there is a lookout point in Atlantic Highlands which at a mere 250' above sea level is the highest point on the Atlantic coast from southern Maine all the way to the Yucatan (believe it or not!). It's hard to describe the road off of Hwy 36 so you'll have to follow your nose. You can also stop in at Belford/Port Monmouth. There is a commuter ferry that runs from the docks there to NYC. This is actually a little section of Middletown Twp that fronts on Raritan Bay. There is a seafood restaurant that people seem to like and an active fishing coop dock on the little inlet there. Also, bordering the inlet is a residential community known as The Dunes at Shoal Harbor. You can park next to the boardwalk and walk onto the beach from there. There are usually a lot of fishermen out on the beach. There is no need to feel shy about wondering into the neighborhood and parking there. Even though it looks private, CAFRA regulations dictate that the parking and access to the beach via the boardwalk is public. I should know, I had it designed, approved, and built. On a clear day, this is a good place to view Manhatten from a perspective looking directly thru the Verrazano Narrows bridge, even if it is a long way in the distance. Another destination would be Keyport, which is turning into a nice little town with some home port character. There is a yacht club with a large mooring field and a marina right in town there. To me, this has more to offer than Perth Amboy, which I would avoid for not having much to be interested in.
Closer to Sussex is Lake Hopatcong, but everybody is pretty much out of the water by now. I went over to the marina to remove my sails last Sunday only to find that our boat is on blocks for the winter. Lee's Park is a nice spot and is probably open because the fishermen are still using the ramps. The water level is dropping for the winter by now and just about all the boats are winterized.