Volunteer skippers have strung their boats with lights and cruised the rivers every December for about seven decades, and the fleets sail most nights from December 3 to 20. The Willamette fleet leaves RiverPlace Marina for runs toward Johns Landing, the Fremont Bridge or Milwaukie; the Columbia fleet works from the M. James Gleason Boat Ramp toward Vancouver, Hayden Bay and North Portland Harbor. Bring a thermos, check the route for your night, and find a spot along the water.