Sorry, not for underwater but....Peak Design Capture Clip, works to fix all their attachments to your backpack strap, waist band or belt. Also the Lens Quick Change holder. Will hold two Sony mount lenses. Going for a hike you can swap between lenses without digging around in your backpack. The Clip and Lens holder are versions 2. So the Lens Holder DOES NOT rotate. Both pcs sold for $54 each. Will sell both pcs for $60 together.
