I’m posting this just as a general FYI. Our system current is the main electronics housing and a battery housing connected with the T200 thruster cable (high temperature PUR subsea cable in the store). In leak testing our system we have noticed that if the battery housing is open and we evacuate the electronics housing, then it will not hold a vacuum. Similarly, if both housings are sealed and you apply a vacuum to the electronic housing a vacuum is generated in the battery housing. This just indicates that air is allowed to pass along the interior of the subsea cable.
This is noteworthy since if one of the connected pressure housing seal’s fail then both compartments can fail. Also of note, a cut or break of the exterior cable housing could case either or both pressure housings to suffer a leak.