The US Coast Guard issued a Policy Letter regarding electronic versions of navigation publications onboard US vessels.  It provides that, pending future regulatory guidance, US vessels may maintain required navigation publications (such as the Light List and Coast Pilot) in an electronic format on the vessel so long as it is reasonably accessible to the crew.  A back-up copy must also be maintained on the vessel.  “Publications”, as defined in this policy, does not include nautical charts.  (11/26/10).