obliged to turn ALUMINAUT 360 degrees in 

 an attempt to locate the pinger; this was 

 unsuccessful and ALUMINAUT then re- 

 quested PRIVATEER to furnish a course to 

 the pinger which it would follow with its 

 gyrocompass. The array was found and it 

 was followed to the original top current me- 

 ter. On reaching the top meter, ALUMINAUT 

 reversed course to follow and ascertain the 

 array's configuration and determine whether 

 or not the release mechanism had func- 

 tioned. Periodic fixes were obtained on ALU- 

 MINAUT from the surface so that the array 

 might be plotted and found again on the 

 subsequent dive. The array was easily fol- 

 lowed, and no trouble was experienced until 

 the line turned at a right angle to its initial 

 trend. At this point the bottom sloped ab- 

 ruptly to the left, and the current measured 

 0.4 knot. To follow the array line it was 

 necessary to change course to starboard into 

 the current which was setting on ALUMI- 

 NAUT's starboard side. The increased cur- 

 rent would not allow the pilot to swing 90 

 degrees to the right and instead caused ALf/- 

 MINAUT to drift to port away from the line. 

 Visual contact was lost, and ALUMINAUT 

 was forced to run with the current downslope 

 until it gained sufficient speed to turn 180 de- 

 grees in a wide arc back into the current. Visual 

 contact with the array line was re-established 

 while stemming the current. Visibility, at 60 to 

 80 feet initially, had diminished to 30 feet at 

 this point. Approximately 15 to 20 feet from the 

 array anchor and release mechanism, the star- 

 board shot ballast tank malfunctioned and 

 dropped its shot, causing ALUMINAUT to lose 

 negative buoyancy and to ascend gradually. To 

 deter the loss of negative buoyancy the pilot 

 stopped ALUMINAUT with the vertical thrus- 

 ter. When ALUMINAUT attempted to get un- 

 derway again, it could not overcome the cur- 

 rent, and was carried down-current again while 

 slowly ascending. At this stage the vertical 

 motor failed and the pilot was forced to drive 

 ahead full with the stern propellers while at- 

 tempting to put a down-angle on the bow with 

 the diving planes. This was not successful, and 

 all personnel moved to the bow in an attempt to 

 increase the down-angle. This failed and 

 ALUMINAUT finally surfaced without inspect- 

 ing the release mechanism. 



Prior to the second dive a retrieving spool 



was installed, and to compensate for the 

 southerly-setting current ALUMINAUT was 

 towed V4 mile northeast of the array location 

 and then commenced to dive statically (with- 

 out power) with a southerly heading trying 

 to pick up the 37-kHz marker pinger on the 

 repaired CTFM. 



Bottoming at 3,400 feet, ALUMINAUT 

 trimmed and continued attempts to locate 

 the pinger. Although the pinger was nearby 

 during the descent, after reaching the bot- 

 tom it was never heard from again. The 

 subsequent 3 hours and 51 minutes were 

 spent looking for the array by following 

 courses given ALUMINAUT by PRIVATEER. 

 Subsequent measurements of the positioning 

 system showed that an error of at least 300 

 yards existed. A final solution was obtained 

 by estimating the submersible's position 

 through depth measurements and bottom 

 slope directions communicated to the surface 

 by the pilot. 



ALUMINAUT's progress was slowed consid- 

 erably by the need to negotiate rock outcrops 

 without use of the broken vertical motor. 

 Objects on the CTFM and side scanning 

 sonars also slowed progress for it was neces- 

 sary to identify each of these objects. At one 

 point tracks, suspected to be from ALUMI- 

 NAUT''s previous dive, were discovered and 

 followed until they finally disappeared. 



While ascending up and over an uneven 

 bottom slope, one of the submersible's pas- 

 sengers walked forward and caused a down- 

 angle on the bow; this in turn caused the 

 spool to strike the bottom and disengage 

 from its carrying hook. Retrieving and re- 

 placing the spool on the hook consumed con- 

 siderable time because of the decreased visi- 

 bility caused by sediment stirred up by the 

 manipulators. 



Finally locating the array, ALUMINAUT 

 attached the retrieval line and surfaced. At 

 the surface the array was transferred from 

 ALUMINAUT to PRIVATEER and recovered. 

 ALUMINAUT's problems in this retrieval 

 contain all the elements that act to inhibit 

 undersea search, survey and salvage. There 

 is, however, one salient point to bear in 

 mind: The array was recovered and not be- 

 cause of the tracking system but in spite of 

 it. 



There is a further aspect of this tracking 



500 



