Thanks again for the info. I just met my RX100 today so I'll get familiar with it then decide whether and how to house it.
I'm not working on the Mermaid or any other boat at the moment. I worked on the Santana liveaboard for a few years from Phuket, then later for half a year on Nai'a in Fiji and Tonga.
I would appreciate if you would contribute to my blog once you get to grips with the rx100 with your comments