In 1953 Rolex had the Submariner prototype tested in deep waters and on a rough terrain by various explorers. More than 1,000 dives later the watch kept ticking, having survived sub-zero temperatures, as well as the wear and tear of expeditions. In subsequent years, as the popularity of scuba diving and other aquatic exploits grew, the Submariner underwent numerous facelifts and design improvements, such as a bigger, easier-to-read 40 mm dial, and a flat sapphire crystal, which replaced its slightly domed Plexiglas predecessor. Early all-steel watches were complemented over the years by gold and Rolesor models.
In 2003, in time for Submariner's 50th birthday, Rolex launched the commemorative model featuring a black dial with a rotatable green bezel, and a stainless steel, oyster flip lock bracelet. (e.g.Rolex Replica Submariner 50th Anniversary)
