PREFACE 



The Naval Civil Engineering Laboratory has been conducting a 

 research program to determine the effects of deep ocean environments 

 on materials. It is expected that this research will establish the 

 best materials to be used in deep ocean construction. 



A Submersible Test Unit (STU) was designed, on which many test 

 specimens can be mounted. The STU can be lowered to the ocean floor 

 and remain there for long periods of exposure. 



Thus far, exposures have been made at two deep-ocean test sites 

 and at a surface seawater site in the Pacific Ocean. Seven STUs have 

 been exposed and recovered. Test Site I (nominal depth of 6,000 feet) 

 is approximately 81 nautical miles west-southwest of Port Hueneme, 

 California, latitude 33°44'N and longitude 120°45'W. Test Site II 

 (nominal depth of 2,500 feet) is 75 nautical miles west of Port Hueneme, 

 California, latitude 34°06'N and longitude 120°42'W. A surface sea- 

 water exposure site (V) was established at Point Mugu, California, 

 (latitude 34°06'N and longitude 119°07'W) to obtain surface immersion 

 data for comparison purposes. 



This report presents the results of the evaluation of the differ- 

 ent alloys exposed at the surface immersion site for periods of 12 and 

 18 months. 



MBL/WHOI 



D 0301 Q0MD117 2 iii 



