I wanted to limit the materials to as much plastic as possible so as to avoid corrosion from salt water.
Originally I was just going to make a simple, short hand-held grip for the camera, but found some PVC fittings that would allow for a cheap and easy extension section.
Basic materials are PVC conduit (electrical) and fittings and Lexan
3/4" schedule 40 PVC conduit left over from previous project (surf fishing cart). Cheap from Home Depot (HD). I used a short length for the hand grip and cut a longer section for an extension section.
.093" thick Lexan (polycarbonate) sheet left over from previous projects (motorcycle wind deflectors). 8" x 10" sheet $4 at HD
3/4" threaded conduit fittings - (2) male and (2) female - less than $.40 each
3/4" pipe cap (from plumbing section, that's why it is white) - less than $.40