photo-taking works and aerial triangulation works for the 2 or 3 areas in which 
each area includes the important habour. 
The Deep-Sinking Vessel ied as Shinkai was used for the photo-taking works 
in the deep water for the topographical mapping of the bottom area under the sea 
specially designed to 35 mm water cameras were used for that purpose.besides 
the l6 mm movie camera placed at the head of the ship body. 
Besides the above mentioned works, the Hydrographic Office has done the 
research works for the volcano precaution at the sea bottom using the 35 mm 
camera from the YS-1l plane.on Jan. in 1970. 
The traffic conditions along the ship route area were measured by the photo- 
grammetric work and the result of the measurement based upon the vessel 
classification and the velocity was effectively used for that purpose. 
- 10 i= 
dev