Cocopuffs-
You might want to get some
charts and look them over. At least on the NY side, you will find there are some places you can access, and others where you may get in trouble. For instance, no boats, including dinghies, are allowed within 1000' of any NYS swimming beach, so any state park with a beach is forbidden unless you SWIM in. County and town parks may have the same
rule. Now, there are also county lands that are not formal parks (i.e. no lifeguards, no formal swimming beach) that would allow you to land a dinghy, but a number have rocks
offshore that might bite your boat.
And of course, private landowners tend to look askance at boaters. The dockmaster at your marina, or other boaters, or even the guys at the local
chandlery, might be good sources of information for you. There are some places like Rineheart's (sp?) in Bayville that actually have their own private beaches. If they are still there, they used to welcome anyone who came ashore (boats and even seaplanes) to have a meal, visit the bar, or hang out on the beach. (Haven't been there in a while but it was a nice place.) Move down a couple of hundred yards to the private town beach, and the story changes.