contacts. Early the following morning (6 

 July) the Coast Guard informed the support 

 craft that the small boat and its occupants 

 had been picked up by a Spanish fishing boat 

 which had planted the buoy to which they 

 had tied their craft. 



Submersible: ALVIN Date: 1965 Reference 



(16) 



Incident: Diving off Bermuda, the tele- 

 phone communications failed and the sub- 

 mersible was separated from the mother ship 

 for 10 hours. The surface ship began search- 

 ing without knowing in which direction the 

 submersible lay. In addition, radio communi- 

 cation failed, requiring assistance from 

 Coast Guard aircraft to re-unite the vessels. 



Environmental Hazards (Natural) 



Submersible: ALUMINAUT Date: NA Ref- 

 erence (1) 



Incident: While on sea trials in Long 

 Island Sound, ALUMINAUT lost depth con- 

 trol and made a rapid excursion toward the 

 bottom. The operational area crossed the off- 

 shore mouth of the Connecticut River. The 

 submersible, trimmed for salt water, became 

 heavy as it entered the fresh water river 

 flow. The change in buoyancy was calculated 

 at 3,500 pounds. Immediate action was to 

 blow ballast tanks, drop shot and power up 

 with the vertical propeller. Subsequent 

 water sampling showed fresh water down to 

 120 feet. The operating area was shifted to 

 avoid the effects of the river. 



Submersible: DEEPSTAR 4000 Date: 21 

 November 1967 Reference (11) 



Incident: Diving off the island of Cozu- 

 mel, Mexico, DS-4000 was proceeding up- 

 slope from 4,000 feet deep and observed a 

 weak current setting SSW, with a 0- to 0.1- 

 knot drift between depths of 3,350 and 1,400 

 feet. Ascending through 1,400 feet another 

 current setting NNE was encountered. The 

 speed of this current increased rapidly as the 

 submersible proceeded upslope and reached 



almost 2 knots at a depth of 900 feet. This 

 strong current was accompanied by reduced 

 visibility and made it impossible to control 

 the vehicle. The dive was aborted and the 

 vehicle was forced to surface. A similar con- 

 dition occurred on the following dive off Mis- 

 teriosa Bank in the Caribbean; in this case 

 the dive was aborted at 2,550 feet when the 

 submersible was swept into a spin. 



Submersible: FNRS-3 Date: 1955 Refer- 

 ence (2) 



Incident: During a dive into Toulon Can- 

 yon the bathyscaph bottomed on a mud shelf 

 at 4,920 feet. While ascending from the shelf, 

 the bathyscaph's guide chain apparently 

 broke loose a block of mud causing a mud 

 slide or turbidity current. A sediment cloud 

 was generated which reduced visibility to 

 zero. In an effort to steer clear of the sedi- 

 ment cloud, FNRS-3 proceeded across the 

 canyon on a descending course and ran into 

 the opposite wall at a depth of 5,250 feet. 

 After more than an hour's wait, the sedi- 

 ment cloud, caused by impact with the oppo- 

 site wall, had not cleared; the vehicle began 

 ascent and at a height of 800 feet above the 

 bottom visibility returned. 



Submersible: ALUMINAUT Date: Febru- 

 ary 1966 Reference (12) 



Incident: During a search for a lost hy- 

 drogen bomb off southern Spain, the sub- 

 mersible had occasion to make frequent con- 

 tact with the soft, muddy bottom. Openings 

 in the vehicle's keel, to facilitate flooding, 

 acted as scoops through which sediment en- 

 tered and accumulated. When this situation 

 was finally noted, the submersible had 

 picked up an estimated sediment weight of 

 4,000 pounds. 



Submersible: ALVIN Date: 1967 Reference 



(13) 



Incident: ALVIN was on a routine geol- 

 ogy dive on the Blake Plateau, off Charles- 

 ton, S.C, when shortly after landing on the 



691 



