Rolex produced specific models suitable for the extremes of deep-sea diving, caving, mountain climbing, polar exploration, and aviation. Early sports models included the Rolex Submariner (1953) and the Rolex Oyster Perpetual Date Sea Dweller. The latter watch has a helium release valve, co-invented with Swiss watchmaker Doxa, to release helium gas build-up during decompression. The Explorer (1953) and Explorer II (1971) were developed specifically for explorers who would navigate rough terrain, such as the world-famous Mount Everest expeditions. Another iconic model is the Rolex GMT Master (1954), originally developed at the request of Pan Am Airways to provide its crews with a dual time watch that could be used to display GMT (Greenwich Mean Time), which was the international time standard for aviation at that time and was needed for Astronavigation during longer flights. To date, the Rolex is the most sought after luxury watch in the world. They also retain the highest percentage of their original value in the industry. With a steady 2,000 watch production per day, Rolex watches has created and maintained a demand for superior watches that are a status symbol which will stand the test of time. The Rolex Oyster Perpetual Submariner watches came into existence in the early 1950's when scuba diving was just becoming the newest trend. Divers demanded a watch that can go up to 100 meters / 330 feet underwater and Rolex answered this demand and developed the first ever water resistant watch; the Rolex Oyster Perpetual Submariner. This soon became the divers' chronometer of choice. The Submariner and Submariner Date models use Rolex perpetual movements, the 3130 and 3135. These movements are certified Swiss chronometers, a title designated for only the finest of high-precision watches that have passed the Swiss Official Chronometer Testing Institute tests. After the introduction of this iconic, yet highly durable watch, Rolex allowed this design to evolve and had since equipped their new watch designs with numerous patented technical innovations. Divers have henceforth continued to praise the Rolex Oyster Perpetual Submariner both underwater and on dry land.
Although the first Rolex GMT Master model was available only in stainless steel, as it was created as a functional work watch, Rolex has been making luxury versions in both mixed steel and gold, and all-gold since the 1950s, and there are even {special|exotic variations that have elaborate designs that use precious stones. As I mentioned earlier, the Explorer II wears a little slimmer but is a touch wider than the GMT II, so which one you prefer comes down to personal preference and the kind of clothes you wear. If you tend to wear tighter fitting shirts and jackets, then you might find the GMT Master II more likely to get stuck on your cuffs. The most obvious difference between the watches is in the bezel. The Explorer II has a fixed bezel in brushed stainless steel and engraved 24-hour numerals painted black. The GMT Master II comes with a Cerachrom bezel and this, if you like the look of it, has some clear advantages. Ceracrom is a ceramic compound made and developed exclusively by Rolex. It’s almost entirely scratch-resistant and is unaffected by UV rays. It’s being used more and more by Rolex and features in the latest Submariner and the recently released Cosmograph Daytona. The numerals are etched into the bezel and then coated with a layer of platinum for maximum legibility and durability.
The Rolex GMT-Master wristwatch was originally designed in collaboration with Pan American Airways and issued by the airline to their crews on long-haul flights. ("GMT" in the name stands for Greenwich Mean Time also known as Coordinated Universal Time). The original GMT Master watch has a 24-hour display fourth hand complication directly linked to and displaying the same time zone as the standard 12-hour hand. This GMT hand enabled the crews to set the watch to GMT or another time zone, and, using the rotatable 24-hour scale bezel, set to the correct offset, a second time zone could be read. GMT or UTC is the time zone that is required for all aviation planning, weather forecasts, schedules and other paperwork. An updated Rolex GMT Master II was released in 2005. This new model features a number of technical changes, such as Rolex's patented Parachrom hairspring as well as a larger Triplock crown (from the diver's watches). The new model also has several cosmetic changes, such as larger case, hands and hour markers and also a new bezel made using an extremely hard ceramic material that is designed to be more scratch and fade resistant. Also included in the update is a new and more luxurious style of bracelet that has heavier solid links and a machined clasp. The stainless steel version now joins the precious metal versions by having highly polished centre links on its bracelet, which gives the watch a more dressy appearance but can be prone to scratches when used as an everyday watch.