Nemrod were a pioneering Spanish manufacturer of diving equipment. They originally made spear-guns but soon expanded to produce a wide range of products. Their Snark III regulator remains the only three-stage regulator ever made. In the United States they were marketed by the Seamless Rubber Company who produced this lavishly illustrated catalogue for 1970. They used the cover again the following year and I'm assuming this also applies to the interior artwork. I'm afraid I don't know who the artist was but I really like the style they employed here.