The problems of naval aerial photography are quite different from those of military aerial work, and on the whole they are more simple. At the same time, photography has played a considerably less important part in naval aerial warfare than in land operations. Photography as a necessary preparation for attack has not figured in naval practice nearly so much as have the record and instruction aspects. To some extent this is due to the nature of the naval operations in the Great War, to some extent to the limitations of ceiling and cruising radius of the naval aircraft. A photographic reconnaissance, preceding and following a bombardment of shore batteries; a photographic record of the ships at anchor, as at Santiago; a photograph of the forts defending a channel, as at Manila; photographs, quickly developed and printed, of an approaching fleet—all these are possibilities of great usefulness in naval warfare between contestants both of whom “come out” and carry the struggle to the enemy's gates. But in the recent war the use of the submarine, operations under cover of fog, the striving for “low visibility,” and the considerable distances to be traversed to reach the enemy lairs, have conspired to limit the development of photography as a major aid to naval combat. Probably when the whole history of the conflict is told we shall learn that the Zeppelins which cruised over the North Sea, keeping the Allied fleet under observation, had a regular routine of photographic work. In the Italian zone, where much of the enemy territory and several important naval centers lay at only short distances over the Adriatic, the naval photographic service more nearly rivalled that of the army than in the English, French and American zone of activity in the Channel and North Sea. [Illustration: FIG. 175.—A lighthouse, as the naval flier sees it.] [Illustration: FIG. 176.—A threatened submarine attack. Throwing out a smoke screen to protect a convoy. British official photograph.]