Brian-
    My through-hulls all have valves.  Cheap easy insurance. Even 
    electrical. A gate valve can cut wire... just in case.
    I saw Deepflight a couple weeks ago and heard nothing about 
    "decommissioning". I suspect someone's confusing it with the embolism 
    machine, Wet Flight.
    Peter "1 atm" K
     
    
    
      Paul,
                 What 
      is this about deepflight being "decommisioned" ?    Do you 
      mean that they are just not running the sub anymore or what?
       
      My sub is loosely based on deepflight's 
      design.
       
      Brian