UNDERWATER DISTANCE MEASURING DEVICE

PURPOSE:To enhance accuracy of measurement of underwater distance such as distance between underwater structures and to facilitate the measuring work. CONSTITUTION:An indirect length measuring jig 11, in which an end fixing material 22 is fitted to an end of a wire material 20 and a marking plate 23 is fixed to the other end thereof, is used. The end fixing material 22 is fixed to one side measuring point while the marking plate 23 is slidably retained at the other side measuring point, and specific tension is imparted by a buoyancy body 15. A measuring point is marked on the marking plate 23 to be brought on land, where the same tension as that by the buoyancy body 15 is applied to the jig 11 so as to measure length from a reference point on the side of the end fixing material 22 to a marked position on the marking plate 23.