It wouldn't be my first choice to keep a saiboat with a 4 foot keel. But, Hey the price is right!!
Chef's right, the best sailing for that depth is south of the Tom's River Bridge.
North of the bridge you'd need to stay close to the channel or acquire local knowlege..( often the hard way).
I kept my 3'6 draft vessel in Bayville for a number of years, and found bottom on more than a few occassion. Most of the time it's muck. I've also been stuck at the dock ( on the bottom) a few times..when a good west wind keeps the bay low.
Try it, you can always move it.