A lot of Kickstarter projects are launched with little more than an idea and a mockup, but the tentatively named FourPro iPhone underwater housing was field tested while filming great white sharks. So I think it’s already proven itself.
Sometimes shooting in the open water just doesn’t make sense: You need sets, lighting, equipment and crew; you need proximity to the airport, and your lead actress’ home in London. You need Pinewood Studios’ 1200-litre underwater stage.