To a land-dweller traveling the ocean, the vast expanse may seem featureless but the reverse may be true for a seabird blown over land by a storm. In the latter situation the differences in vegetation and topography "obvious" to land-dwellers are completely foreign to a seabird as it has had little previous experience to help interpret these "strange objects." Griffin and Hock (1949) observed the flight behavior of gannets displaced far inland away from their nests. The bird appeared to search randomly until the coastline was met, then the fliers pursued a much more direct course home. Herring gulls, displaced about 250 miles from their nest in 2 consecutive years, returned the second year in one-sixth the time required the first year (Griffin 1943). To birds such as gannets, albatrosses, and shearwaters, which spend almost their entire lives traveling thousands of miles at sea and return to very specific nesting areas, the "featureless ocean expanses" are probably very rich in visual cues. It is difficult to believe a bird dependent on the sea for its livelihood cannot help but be aware of wave direction, islands, reefs, atolls, concentrations of floating flotsam, organisms, currents, clouds over islands, fog belts, etc. Much migration takes place at night and great stretches of the open sea are crossed to reach destinations. Nights are rarely so dark that all terrestrial objects are totally obscured, and features such as coastlines and rivers are just those that are most likely to be seen in the faintest light, particularly by the acute vision of birds from their aerial points of observation. Even if terrestrial objects are completely obscured on a very dark night, the migrants are still able to assess their surroundings during the day before starting out again. Some birds, especially colonial seabirds, seem to be able to fly unerringly through the densest fog, particularly in the vicinity of their nest site. Members of the Biological Survey, proceeding by steamer through a dense fog from the island of Unalaska to Bogoslof Island in the Bering Sea, recorded flocks of murres, returning to Bogoslof after quests for food. The birds broke through the wall of fog astern, flew by the vessel, and disappeared into the mists ahead on the same course as the ship. On the other hand, radar observations of migrating birds have indicated strong directional movements on clear nights but often completely random movements in heavily overcast or stormy weather. Possibly some birds can perceive the position of the sun through an overcast as honey bees are known to do. It is less likely the stars could be detected through overcast at night.