Not all the homes in Sylvan Beach hake Lake Rights...your Realtor can tell you property-by-property which listings do or dont have rights. I could also set up a search for you that only shows you properties listed that have rights! The good thing about Sylvan Beach is that there a quite a few public places where you can access the water.
Lake rights vary from property to property. Generally I have noticed that homes within about a block of the shoreline have lake rights. If this is an important thing for you, be sure to investigate your choice before making an offer.