With already an extensive experience and history in producing robust tool watches for diving, Rolex pushed its limits even further in the late 1960s when they agreed to partner with the “NASA” of the seas, COMEX. The firm was the most active explorer of the deep oceans, hence an “ultra” diving wristwatch was in need to execute deep sea expeditions. The Rolex ref. 5513 was the initial model that both parties worked on to develop the “ultimate” dive watch. With a daring yet successful idea to release pressure one way, a helium gas escape valve was developed and located on the case band opposite side of the crown. The initiation of the new patent meant an increase in performance and depth of the watch. With the gas escape valve having been tested thoroughly and proved its purpose, the Sea-Dweller was born.

With most examples issued to COMEX specialist divers with a COMEX dial and case back with engraved issue numbers, the 5513 non-logo with helium escape valve is one of the rarest of all. Fitted with matte black no logo feet first dial, the present example is indefinitely rare. Further enhancing the beauty of the present example, the dial is presented in excellent overall condition and also with the diver extension stamped PAT. PEND. The present watch is one of the rarest examples of COMEX issued wristwatches.