Rolex has been manufacturing complicated diver's replica watches that are built to withstand unbelievable depths since the 1950s. Apart from being able to travel far below the surface of the ocean, each Rolex diver's watch boasts a perfect visible dial topped with lume together with a bezel that can be adjusted to measure diving times. The bezel plays a large role in keeping safe time while in the water, as it typically utilizes a unidirectional design, relying on the year the model was launched. While the Rolex Submariner collection first came to market in the 1950s, the bezel was bi-directional. The aluminum inserts boasted 60-minute graduations and a distinct arrow marker at the 12 positions. Serrated edges provided a simple grip for use while in the water. While early generation fake Rolex Submariners were surely impressive for their time, there was much room for upgrades. Between the late '70s and early '80s, the replica Rolex made several important signs of progress to the Submariner, consisting of increased water resistance of up to 1,000 feet, the addition of a sapphire crystal, and a unidirectional bezel. The bezel was also upgraded to a ceramic insert in later models. The unidirectional bezel was an extremely important upgrade, as it allowed time to move forward only, never backward. This feature is invaluable during deep saturation dives when every second matter. To use the Submariner's time-lapse bezel, rotate the zero-marker to the left, stopping at the minute hand. This should be done before descending into the water. Your diving time will be tracked on the bezel via the minute hand as time passes. The unidirectional design is added as a safety precaution; even if the bezel is bumped or moved your diving time will only get shorter. The Sea-Dweller replica watch is another diver's watch produced by Rolex. While it functions similarly to the Submariner, the Sea-Dweller stands apart from Rolex's iconic diver with an increased depth resistance of up to 4,000 feet. Similar to the Submariner, the Sea-Dweller debuted with a bidirectional bezel, which was later replaced with a unidirectional variation with the addition of reference 16600. Its purpose is the same as the Submariner bezel, to measure decompression stops and other diving times. Similar to the Submariner, the Sea-Dweller bezel can be used to measure diving times by turning it counterclockwise to coordinate with the minute hand on the dial. While the Rolex replica was not the first company to make a diver's watch, they are absolutely the most iconic, setting the standard in the industry for quality, function, and style.