Navesink Beach is an unincorporated community located within Sea Bright in Monmouth County, in the U.S. state of New Jersey. It is one of the four main built-up areas of Sea Bright and is the northernmost settled area of the borough. Navesink Beach is a former stop on the New Jersey Southern Railroad. The Sea BrightâÂÂMonmouth Beach Seawall passes through the neighborhood and Normandie.