Orthophotography removes the normal distortions in aerial 

 photographs caused by the tilt of aerial cameras and varying ground 

 elevations. The result is a precise photograph in which the horizontal 

 positioning of surface features is correctly depicted. The random dot 

 printing of negatives retains important details that are commonly 

 lost in other methods of reproduction. 



Harbor charts incorporating these techniques will combine 

 standard hydrographic information such as water depth contours 

 and bottom characteristics, with random dot printing of 

 orthophotographs of the adjacent land areas. Prototype charts of this 

 type have been well received, and a chart of Fort Pierce Harbor, 

 Florida, has been issued. Similar charts of four other Florida harbors 

 are now in the planning stage. 



Deepwater Ports 



No existing U.S. harbor receiving crude petroleum has either the 

 facilities or the natural depths to handle supertankers ranging 

 upward to 540,000 dwt and drawing as much as 94 feet of water. 

 Moreover, problems resulting from this inadequacy to handle large 

 ships are becoming more severe because the increase in vessel size 

 being experienced in the shipment of crude petroleum is now 

 beginning to develop, although to a lesser extent, in the shipment of 



Detail from chart of Ft. Pierce, Florida 



68 



