So I went diving for the first time with my new rig, sony a7rii 28mm with 16mm conversion Ikelite housing no flash as I couldn't get my Inon z240 to work (think I have it working now). Not the best of images finding that underwater is going to be a lot harder than I thought. But can't wait to get out and do it again. Thanks everyone on the site for all the help so far.