(Fig. 2), the seaward side. The maximum elevation on the island 

 is 1962 ft at Mount Thirst. 



The San Clemente Island area offers an environment, climatic and 

 underwater, totally amenable to a wide variety of ocean science and en- 

 gineering experimentation. There, equable temperatures (~80°F high and 

 ~45°F low) and calm waters prevail approximately 300 days a year. As 

 a result test programs which require surface support ships and good 

 visibility can be accomplished with a minimum of lost time. 



The water surrounding SCI is relatively clear, with good underwater 

 visibility to a distance of 75 ft at 100 ft depths from January through 

 March. Increased marine life and other suspended material during 

 warmer months generally limit visibility to approximately 30 ft. The 

 ocean floor near the Island is composed of smooth gray sand, primarily, 

 with occasional rock outcrops along the underwater ridges. Water depths 

 increase rapidly on the east side, averaging 1,800- to 2,000-ft one mile 

 from shore, with depths to 4,200 ft available within three miles from shore, 

 and 6,000 ft and 12,000 ft depths nearby. The slope of the ocean floor on 

 the west side, where the depth averages only 300 ft. one mile from shore, 

 is much more gentle. 



The Ocean Engineering Range has been used for missile and torpedo 

 programs. One missile program, SUBROC, involved the developmental 

 and technical evaluation tests of live SUBROC missiles. These tests re- 

 qmred extensive communications, photometric data coverage, telemetered 

 data-recording capabilities, radio-destruct precautions (Command Flight 

 Interruption), and numerous launch site, range length, and target condition 

 configurations. The Antisubmarine Rocket (ASROC) weapon system was 

 conceived, developed and tested by NUC. Firings are conducted at SCI 

 either from shipboard within range of instrumentation sites, or from one 

 of two permanent launch pads, depending on the type of target site. The 

 Mk 46, Mk 44, Mk 43 Mod 0, and Mk 43 Mod 1 torpedoes have been tested 

 at the Island. These tests were captive warshot rims, airdrops, or 

 ASROC flights delivering free-running torpedo payloads to the target area. 



Airdropping instrumented test packages into waters off the Island is a 

 major activity involving all types of aircraft. Some programs are for the 

 evalxiation of aircraft and release mechanisms rather than the hardware 

 being dropped. Past tests have included JATO-boosted imits, free-fall 

 units, parachuted vmits, torpedoes and depth bombs. Nearly all drops 

 must be supported by photometric and telemetric data-acquisition systems. 



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