Just had an email from the people at indipod
"The indipod was designed for use within vehicles but it can be used outside the vehicle with an added extension connector back to a 12 volt socket. What is the voltage on your RIB? We also have a 24 volt version of the indipod.
However, there is one minor drawback! When used inside a vehicle the specialised automotive Velcro, which is on the top of the privacy bubble, attaches itself to the headliner and does not allow the bubble to collapse when the entrance door is opened. Therefore when used outside there is no point of attachment and the bubble will de-pressurise and deflate momentarily as the door is opened but will re-inflate as soon as you are inside (this takes about 10-15 seconds). From them on the functionality is exactly the same.
It is stable when used outside as the weight of the base unit and your own weight when inside the privacy bubble gives it stability. But as it was designed for use inside and not on a boat, we have not tested it in windy conditions at sea! Although I have no doubt it will perform admirably"
So it DOES seem to be suitable - looks like a certain person who MUST be obeyed will get her way after all.........