In the history of our deep dive Rolex Sea-Dweller Replica watches, we take a look at the watch which is often called the “Triple Six” and considered a transitional reference. Many changes have been brought by this Sea-Dweller to Rolex’s extreme diver’s watch. Let’s explore the Sea-Dweller “Triple Six” in more detail.
The first launch of the Replica Sea-Dweller was in 1978. Astonishingly, Rolex did not break off the creation of the previous Sea-Dweller “Great White.” Somewhat, both references were available next to each other for a few years. In all probability, this was because, even though they used the same model name, they were different beasts indeed.
And at present, traditional Replica Rolex Sea-Dweller Triple Six boasted many changes. At first, its water-resistance doubled to 4.000 feet (1,220 meters). As a tool watch positioned for deep-sea divers, this was definitely a useful and extraordinary improvement. The enhanced water depth rating was thanks to some extent to a larger helium escape valve (HEV). A quick refresh, the HEV is the Rolex-patented mechanism that admits watches to correctly decompress when resurfacing. That is, the HEV mechanically releases built-up helium (and other gasses) from the watch. The releasing of the gasses fundamentally normalizes differences in internal and external pressure, therefore disputing the crystal from bursting off or other damage to the watch.
A sapphire crystal on the dial of the Rolex Triple Six always protects the dial. Certainly, sapphire crystal is now average across all Rolex watches, particularly prized for its scratch resistance. Like all versions of the Sea-Dweller (up until the most recent version released at Baselworld 2017), the sapphire crystal on the watch does not comprise a Cyclops enlargement lens above the date window. 
Besides, on the top of the watch was now a unidirectional bezel rather than a bi-directional one. Unnecessarily, this is much safer for divers since overestimating immersions times is far better than underestimating them.
As well as the above modifications, there is a novel automatic caliber ticking inside. The original Replica watch housed Caliber that replaced the Caliber of the preceding Sea-Dweller.
The novel beautiful Caliber operated at a higher frequency—28,800 beats per hour rather than 19,800 BPH. Furthermore, it was also a much-appreciated feature for a strong dive watch.
A fantastic realistic improve that was the quickset date feature the Caliber watch brought to the Sea-Dweller. This now meant that owners could set the date promptly, having nothing to do with the hour hand.