33 



polyurethane jacket with double steel armoring and an external 

 polyurethane jacket. The cable weighs 0.98 pounds per foot in air. 



Eighty feet of the seaward end, stripped of its armoring, is 

 stored in an 18 inch square by 9 inch plexiglass service box just 

 before mating with the instrument. The top plate of the box is 

 removable by unthreading four titanium nuts. This accesses the spare 

 cable if the instrument is to be moved or taken to the surface. If 

 the instrument requires service in the boat or on shore, the cable 

 may be disconnected above water, sealed with a dummy connector, and 

 released. A dummy connector is then attached to the instrument for 

 safety. For re-installation at some later time, the cable is 

 recovered, re-connected in the boat, and the instrument is brought 

 underwater. It is hoped that operating the underwater connectors 

 only above water will help alleviate some of the flooding and 

 corrosion problems experienced in the past with underwater-pluggable 

 connectors . 



7. The Electrical System 



Fourteen of the available twenty conductors are utilized. 

 Ten carry the five transducers' signal outputs, two carry the 

 positive excitation voltage (one for back-up), and two carry the 

 negative excitation ground, (one for back-up). Each of the 

 transducers share the excitation positive and negative leads. A 

 simple RC network can be installed at the landward end of each signal 



