For dedicated collectors of vintage Rolex sports watches, most would agree that one of the most celebrated and important collaborations was between Rolex and COMEX. The partnership between the two organizations witnessed their first serially produced wristwatch, the Rolex Sea-Dweller. While its aesthetics remain very much similar to the Submariner, an important feature developed by COMEX would set the two apart, the helium gas escape valve. Attached to the left side of the caseband, the helium gas escape valve allows gas to escape in one outward direction while retaining its waterproof capabilities, enabling for a much deeper depth rating.