Thanks for your answers everyone. We've checked with the retailer but not the manufacturer - excellent suggestion, we'll do it tomorrow.
You may be right in saying that they will not approve the boat installation, in which case we will have to decide, though we're likely to crack on with it.
The stove itself is small 47x28x88cm (Artel Linea Mini) and we're choosing it for three reasons: (1) the environment, (2) programmability (3) ease of use. It has a 10kg tank capacity and can be programmed to switch on and off depending on the ambient temp. We're on residential mooring and storage is no different to coal: all bagged up and sitting in a dry area.
We'll keep checking here for the next several weeks, so if anyone knows an installer, please give us a shout.
Once again, thanks for your help everyone. Appreciated.