Pan American Airways is the biggest of seven giants struggling for transoceanic supremacy.

A polar oriented informational map of the world showing the air routes of Pan American Airways flying boats, aka clippers. The Pam Am routes are shown in various thickness red lines, narrow 2 flights a week, medium, 3-4, heavy 5 or more. Other airlines routes are also shown in different colors. Inset map show close up of the Caribbean and the routes and type of aircraft flown which include Sikorsky, Douglas DC-2's, Ford Tri-motor and Lockheed Electras and Orions.