This is the third in a series of articles about walking from your home in a highly populated area.  Pt Loma to Oceanside is an 11-hour 39-mile marathon kept interesting by the bay, beaches, and bustle of activity along the scenic coastline and Pacific Coast Historic Highway 101..   I walked this twice (returned by car) as a training hike for the 100km one day 100k trek along the Potomac River starting in Washington DC.