The normal work of the Coast and Geodetic Survey, carried on throughout the United States and its possessions, includes (1) surveys of the coastal waters and adjoining land areas; (2) observation, study, and prediction of ocean tides and currents, and of the earth's magnetic elements; (3) geodetic control surveys and related gravity and astronomical observations; (4) production of nautical and aeronautical charts; and (5) seismological observations and investigations. These activities provide information essential for water and air navigation, for mapping, and for many other strategic purposes, and thus assume vital importance in time of war. Personnel engaged in this work acquire training and experience invaluable in many phases of military activities. Beginning during the period when preparations were being made for national defense and continuing throughout the war the Coast and Geodetic Survey was called upon to furnish, in increasing volume, a great variety of products and services which were required for virtually all classes of war operations. Activities of the Bureau carried on for these purposes were principally in the following three categories: 1. Transfer of personnel, ships, and equipment to the Army, Navy, and Marine Corps. 2. Utilization of personnel and facilities remaining with the Bureau for surveys and other investigations required for military and naval operations. 3. Expansion in the production of marine and air navigation charts, special charts and maps, and related material, to meet the needs of the Army, Navy, and Merchant Marine.