These are 5 position alpha-numeric codes comprising the d series. All other level II codes and descriptors are approved and maintained jointly by the alpha-numeric editorial panel (consisting of CMS, the Health Insurance Association of America, and the Blue Cross and Blue Shield Association).
Alaska: Although Alaska enjoys a high volume of aurora activity, its cruises are not often mentioned as northern lights cruises. During the Alaska cruise season, it's rarely dark enough for the lights to be visible.
Cruise & Maritime Voyages (0844 998 3801; cruiseandmaritime.com) has two Northern Lights cruises to Norway and two to Iceland. A 14-night round trip from Liverpool departing on October 3, 2016 on Magellan calls at Dublin, Lerwick, the Faroe Islands, Akureyri and Reykjavik (both overnight).