A Vietnam War-era USAF aeronautical planning chart, Special S.E.A. Operational Navigation Chart sheet SOC-1, covering the Vietnamese coastline and adjoining waters of the Gulf of Tonkin and Gulf of Thailand. Printed at 1:1,000,000 scale with terrain relief, elevation data, and overlaid territorial water and air defense identification zone boundaries, charts like this one were essential tools for aircrew flight planning, target orientation, and search-and-rescue operations throughout the war. This example is preserved in the collection of Capt. Bob Karre, USAF. Project: 218850