There are Alaskan cruises that visit glaciers, and then there are Alaskan cruises that visit Glacier Bay. The former are a treat, but the latter are simply spectacular, for Glacier Bay can aptly be described as the crown jewel of Alaskan cruising. This 5,130-square mile national park, accessible only by sea, is a veritable ice-stravaganza, with 1,045 glaciers competing for attention. The National Park Service limits entry permits, thus shutting out most cruise lines completely. Holland America Line, however, has historically garnered a large share of the permits, as has Princess.