Dive Master Reel. This Large dive reel was designed and made by McMahon Engineering Ltd in the early 1980’s. The reel itself is extremely easy to use and robust when used correctly. Can be easily maintained, and extremely easy to replace parts when necessary. The main parts of the reel are made from a polypropylene material and ABS plastic and fixed together with marine quality stainless steel axle bolts and A4 stainless steel fixings.