Boating is business for Karen Miles. She and her family have owned Devil's Elbow on the Intracoastal Waterway near Crescent Beach for more than 50 years. It's a one-stop fishing facility with a boat ramp, bait and tackle shop, boat rentals, and cottages. It's three miles north of the Matanzas Inlet.The Matanzas Inlet in Southern St. Johns County is narrower than it used to be just three years ago because sand has started to fill up the inlet. Wildlife officers say only one or two areas between the bridge pilings are navigable for small boats now.he and her family have owned Devil's Elbow on the Intracoastal Waterway near Crescent Beach for more than 50 years. It's a one-stop fishing facility with a boat ramp, bait and tackle shop, boat rentals, and cottages. It's three miles north of the Matanzas Inlet.