I have decided to break silence and risk being shouted down but i had a small idea. At the moment the route currently seems to be to get a 35mm lens behind a dome. This is of course fine but what about the idea of using an actual underwater lens. You can still buy lenses for the Nikonos RS and it should not be too difficult to machine the mount and the servo controller for focus. Maybe they wouldn't be that good quality but i presume they were made very well originally and you get an image hitting the sensor that has not had to go through glass air then more glass. What do people think about this? OK so it might be a worry having a potential leak so close to the camera but a leak is dodgy wherever it occurs.