What is a Dive Watch?

NAUTIS Stealth 200 in Cool Grey

The very first recorded efforts for water resistant timepieces dates all the way back to the 17th century, with the only true water and dust resistant watches being one-off custom made pieces that were reserved for those of wealthier stature. These specialized pieces were referred to as “Explorer’s Watches”. It wasn’t until the early 20th century that water resistant timepieces were being industrially produced for military and commercial distribution. In 1926, Rolex bought the patent for the “oyster” watch case, featuring a hermetic seal. The watch was put to the ultimate test on a dive through the English Channel, tied to a ribbon around the neck of English swimmer, Mercedes Gleitze. After over 10 chilling hours, she reported that the piece remained sealed and dry, and kept perfect time throughout the swim.

Omega SA has since been credited with creating the very first commercially distributed “dive watch” in 1932. The Omega “Marine” underwent a series of rigorous trials by the Swiss Laboratory for Horology in 1937, and was reported to withstand a pressure of 1.37 MPa (13.5 atm), which is equivalent to a depth of 135 m (443 ft), without any water intake into the case of the watch.

Throughout history, these water resistant timepieces have been sought out and favorited by not only divers and ocean adventurers, but also by military forces like the navy and marine corps. Watch enthusiasts and collectors have also taken a huge fascination in diving watches, due to the uniqueness of their functionality and design.

Obviously, the biggest contributor to the lure of dive watches is their water and pressure resistant design, as well as the piece’s ability to maintain its function in specific depths. Typically, to be referred to as a “dive watch”, the piece is required to have a water resistance greater than 1.0 MPa (10 atm), which is equal to a dive of about 100m (330 ft). Usually companies strive for an ATM of 20-30 in their dive watches, allowing around 200-300m (660 to 980 ft) of dive capability.

Today’s contemporary dive watches will meet the requirements in accordance with the ISO 6425 standard, written by the International Organization for Standardization (ISO). The ISO 6425 standard is responsible for the rules and regulations surrounding the certifications a timepiece must meet in order to be considered suitable for diving. In addition to the water resistance minimum of 100m depth rating, the ISO 6425 Standard, also contains numerous other requirements for diver’s watches. The presence of a unidirectional bezel, clearly distinguishable minute markings, adequate visibility in darkness, and magnetic, shock, and chemical resistance are all examples of requirements for the basic dive watch. However testing for these qualifications is voluntary and accrues its own cost, so many manufacturers will not present their timepieces with this certification.

The case design of a dive watch is pertinent to its functionality and underwater capabilities. Therefore, the case must be adequately water and pressure resistant to be able to endure the galvanic corrosiveness that comes from prolonged exposure to seawater. This is why most cases are made with materials like 316L grade or higher stainless steel, titanium, ceramic and synthetic resin, plastic, and even sometimes brass or bronze with a specialized finish.

In addition to case design, the watch crystal also plays an important role in the water resistant security of the dive watch. Most dive watches are manufactured with a thicker crystal, which is sometimes domed to enhance pressure-resistance, as well as the legibility of the watch face underwater. Typical materials used for a dive watch crystal include acrylic glass, hardened glass, and most commonly, synthetic sapphire. Some companies may manipulate the crystal of their pieces by combining two different materials, like sapphire for it’s anti-scratch properties and hardened glass for it’s durability, to enhance the strength of the watch. And they may even add an anti-reflective coating for better legibility while submerged.

Every component of a dive watch must be water resistant, including the crown. Usually, the crown has to be unscrewed to set or adjust the time and date, then re-tightened to restore it’s water resistant seal. Some watch manufacturers may even install a separate knob, extra crown cover, or locking handle, which must first be manipulated before the crown is able to be operated. Even water resistant crowns should never be operated underwater, as this may cause unwanted water seepage into the mechanics of the piece. Gaskets form a watertight seal in every opening and crevice of the watch, and these are used in conjunction with a special water-resistant sealant applied to the watch case, preventing the presence of moisture inside the piece.

Some dive watches today are designed in order to endure saturation diving, with a helium-release valve. Once the diver is rising back to normal atmospheric conditions, the valve is created to release pressure inside the piece, caused by helium rich environments. If the valve is not used when returning to normal levels, the crystal of the timepiece may shatter due to the immense pressure inside the piece.

Quality of watch straps and bracelets are not only important for the security of your watch around your wrist during wear, but also for comfort while diving and returning to the surface. Dive watch straps or bracelets are typically made up of adequately water and pressure resistant materials, and should also be able to endure the corrosiveness of seawater. Most practical dive watches feature a rubber, silicone rubber, or fabric strap. In other cases, the timepiece may be designed with a more luxurious, titanium or stainless steel bracelet; which may make it easier to wear the piece over the sleeve of a wetsuit, but may also be more susceptible to failure points in the links. A typical rubber or silicone rubber strap will have vented cutouts or rippled sections near the case of the watch to enhance flexibility and comfort during wear on land or in the sea.

The dials and markers on the watch face and bezel are some of the most integral components of the design and functionality of the dive watch. They must be completely legible both underwater and in low-light or total darkness conditions. Because of this, most dive watches will have large, uncluttered dials with high contrasting colors, and an easily identifiable minute hand. Dive watches are commonly designed with the numbers 3,6,9, and most specifically 12; as well as the number 0 on the bezel, to stand out from the rest of the watch face, in order to avoid read out errors. Most companies use luminous phosphorescent pigments like Super LumiNova or tritium based self-powered lighting devices to give their markings a bright glow, making the piece easily legible in dark, underwater environments.

The advancement of modern technology in regards to watch movements and mechanics have paved the way for more luxurious and durable dive watches, which are able to withstand more than double the amount of pressure than where we began centuries ago. Today, thousands of dive brands and watch microbrands are sporting ATMs of 20 or more, and are integrated with multifunctional components like helium-release valves and Super-LumiNova hands and markers. Among these growing brands is NAUTIS, featuring beautiful, yet rugged pieces with 20-50 ATM water resistance and high-quality stainless steel or genuine leather watch straps, like this NAUTIS Stealth 200 in cool grey, https://www.nautiswatchco.com/product-page/nautis-gl2087-g. The stunning, high-contrasting watch faces and dial colors make these dive watches perfectly legible in any circumstance, even when underwater or in total darkness. Designed with precision movements and quality diving capabilities, NAUTIS watches are making their mark in the watch world, and are soon to be on the wrist of every diver, enthusiast or collector you meet.