An underwater vehicle surrounded by an enveloppe of gas or air in a 
supercavitation scheme or else is still under water pressure. in deep water 
water pressure on the hull would be the same than if the water was directly in 
contact with the hull. What keeps the water off the hull exerts the same 
pressure on the hull.
  ----- Original Message ----- 
  
  
  Sent: Tuesday, June 25, 2002 6:59 
PM
  Subject: Re: [PSUBS-MAILIST] Theory 
  Question
  
  James, 
   
  Somewhere in this thread, someone (you?) wondered 
  if a sub wrapped in a supercavitation bubble might be able to operate at great 
  depth without regard for pressure hull strength considerations.  I 
  suppose in theory that's possible, depending on whether or not one could 
  generate a bubble of greater pressure than would be encountered down 
  deep.  However, I don't think it would be wise to rely on such a system, 
  though; for the obvious reasons of what would happen if it failed at greater 
  than design collapse depth.  Whammo!  Your barracuda becomes a 
  flounder!
   
  Pat
  
    ----- Original Message ----- 
    
    
    Sent: Tuesday, June 25, 2002 12:29 
    PM
    Subject: Re: [PSUBS-MAILIST] Theory 
    Question
    
    Oh I definitely understand that, I don't 
    imagine that anyone would want to travel that fast near anything that would 
    come even remotely close to the sub.  I was just wondering if the 
    assumption that supercaviation =  less hull pressure was 
    accurate.
     
    James
     
    ----- Original Message ----- 
    
      
      
      Sent: Tuesday, June 25, 2002 3:16 
      PM
      Subject: Re: [PSUBS-MAILIST] Theory 
      Question
      
      Hi speed for underwater vehicles is suitable 
      only with enough deep waters and "room" around, there is no way you can 
      drive a mini sub at more than 10 m/h in shallow waters or with reefs and 
      obstacle. it s like driving a car in the fog. Even with 100 Ft 
      visibility once you SEE the obstacle the collision is at 5 
      seconds, 5 sec to make a sharp turn or stop is actually not easy 
      at all. Add to that the momemtum  of the sub.
      Herve