Prime Boat Slip for Sale in Waterfront Marina, Downtown St. Joe! Discover the perfect spot to dock your boat with this 30-foot slip in the prestigious Waterfront Marina, ideally located in downtown St. Joseph. Unbeatable Location: Just a few blocks from Silver Beach, a variety of eateries, shops, and downtown St. Joe attractions. Prime harbor location with NO BRIDGES to wait for. The shortest distance to Lake Michigan of any of the Marinas in the area.