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.
In addition to the Northern Lights, Alaskan cruises offer a glimpse at rarely seen wildlife like polar bears, seals, whales and reindeer. The changing of the seasons bring wildflowers in the springtime and colored leaves in the fall, but you can also see never-melting glaciers rising up out of the arctic waters.