ISO 6425 diver’s watches are timepieces that meet the specifications of the ISO 6425 standard, principally water resistance (minimum 100 metres), resistance to external forces, thermal shock and magnetic fields, a dive timing device such as a unidirectional rotating bezel, hands that can easily be read in the dark and are clearly distinguishable one from the other, a way of seeing that the watch is running even in the dark, and so forth. There is a more detailed article on ISO 6425 specifications here. The standard, first published in 1982 and successively updated, was created to help distinguish watches that can be used for diving from other dive-style watches. Watches that comply with ISO 6425 can be marked “Diver’s xxx m” or “Diver’s watch xxx m”.
Generally, manufacturers who wish to launch a model that complies with ISO 6425 test all the units for water resistance, and perform type testing for the other characteristics, in other words, testing just a few samples from each production run. While standard-compliance testing is normally performed by an external authority, most watch brands run the testing themselves and describe their watches as ISO 6425-compliant.
While diving watches represent one of the most popular types on the market, there are very few ISO 6425-compliant watches. Many prestigious brands specifically choose not to mention ISO 6425 or use the word “Diver’s” on the dial, such as Omega with their Seamaster, Rolex with classic diving watches such as the Submariner and Deepsea, Panerai, Blancpain etc. Often high-end brands have their own internal certification departments and so prefer not to mention ISO at all.
On this point, it’s important to underline that diving watches by brands such as Rolex, Omega, Blancpain, Panerai, Doxa etc. are superb timepieces with characteristics that satisfy and often exceed ISO 6425 specifications. Brands such as these have been working on diving watches long before the introduction of the ISO standard, and so they are entitled to consider that their own internal standards are absolutely legitimate. ISO certification is voluntary and in no way mandatory for brands making diving watches.
Some classic diver’s watches are now out of production. Cartier’s Calibre de Cartier Diver’s watch was discontinued in about 2018. The legendary ISO 6425-compliant Seiko SKX007 – a much-loved low-cost diver’s watch – is no longer in the brand’s catalogue. But in the current situation, with the constant arrival of new brands utilizing delocalized production and using social media to drive sales, there are some new arrivals. Amongst budget dive watches, Helm is an American brand that has understood the marketing potential of ISO 6425, and three of their models are compliant with this standard.
The watches below are listed in ascending price order.
1. Helm Vanuatu
The Helm Vanuatu ISO 6425-compliant watch is rated at 300 metres water resistance, and it has all the other diver’s watch specifications. The case is 42 mm in diameter and 14 mm thick, in brushed stainless steel. The dial is organized for maximum clarity, with the Helm logo and lettering in relief or subtle grey, and a date window at 6 o’clock that blends perfectly into the design. The watch is powered by the Seiko NH35 automatic movement, 21,600 vibrations per hour, power reserve 40 hours. Helm is an American company founded in 2014, and its watches are assembled in China under their own supervision. You can purchase it from the Helm website for $275 + $35 shipping (total approx €263, plus duty where applicable). Read more abut the Helm Vanuatu on this blog, where there is also a Helm Vanuatu user review.
2. Helm Komodo
The Helm Komodo is a more compact diver’s watch than the Vanuatu, with a stainless steel case 40 mm in diameter. It is ISO 6425-compliant, with a 300 metre water resistance, and it has a screw-down crown and a Seiko NH35 automatic movement. The dial design options include a matte orange version with different lume colours. The date window is neatly incorporated into the layout at 6 o’clock. Available on the Helm website at $285 + $35 shipping (approx. €272).
3. Helm Khuraburi
The Khuraburi has specifications similar to the Helm Vanuatu, with 300 metre water resistance, but the dial design is different, with no date window, and some colourful options based on orange and blue. In the version shown here, the hour and minute hands are distinguishably different in the dark through the use of two lume colours. Available on the Helm website for $300 + $35 shipping (approx. €284).
4. Citizen Promaster Diver
If you don’t mind a quartz movement, this new Citizen Promaster Diver model, reference BN0155-08E Eco-Drive, may interest you: it has an ISO-rated water resistance of 200 metres. Its case is in stainless steel, 44 mm in diameter, and the watch is on a rubber “accordion” diving strap. The unidirectional rotating bezel frames the dial, which has super-chunky hands and indices, and a nicely discreet date window. The watch is powered by the Eco-Drive movement, which has the advantage of being powered by light, so there is no battery to change. The watch is available online at about €313. Read more on the Citizen website.
5. Seiko Prospex SRP777K1 “Turtle”
The “Turtle” is perhaps the most appropriate replacement for the sorely-missed Seiko SKX007. It has a distinctive cushion-shaped stainless steel case 44.3 mm wide and 13.4 mm thick, with 200 metres water resistance and a screw-down crown positioned at 4 o’clock. The automatic 4R36 movement provides about 41 hours of power reserve, and also features day and date indicators. This version is provided with a silicone strap. Price €419. Read more on the Seiko website.
6. Orient Star RE-AU0304L
The Orient Star RE-AU0304L watch is marked “Diver’s 200m” on the dial, and the website description includes a reference to ISO. This 43.6mm-diameter watch has a water resistance of 200 metres, with stainless steel case, screw-down crown, and an F6N47 movement running at 21,600 vibrations per hour, 3 Hertz. It provides 50 hours power reserve, as shown by a hand on a quadrant at the top of the dial. The Orient Star RE-AU0304L is made in Japan by Orient Watch, established in 1950 and now owned by Epson. Price approximately €700. Read more on the Orient website.
7. Certina DS Action Diver
Back in 2018 the Certina DS Action Diver had “ISO 6425” on the dial, but in the latest versions this has been omitted, while leaving “Diver’s Watch 300 m” in place. It is compact at 38 mm, small enough to be unisex, with a steel case and a PVD-coated unidirectional bezel. Inside it has the Powermatic 80.611 movement that provides 80 hours power reserve. There are now many variants available, including the classic black and blue dial colours, and other hues including this green version that recalls Certina’s brand colour. Price €760, available in Certina boutiques. Read more in an article on this blog, or visit Certina’s website.
8. Tissot Seastar 2000 Professional Powermatic 80
Marked “ISO 6425 Diver’s watch 600 m” on the caseback, the Tissot Seastar 2000 Professional Powermatic 80 is rather unusual because it combines impeccable dive watch characteristics, such as 600 metres water resistance, a helium escape valve and ISO 6425 certification, with aesthetic features not usually seen on diving watches, for example the display caseback and a graded dial with an engraved wave pattern. It is a large timepiece at 46 mm diameter and 16.3 mm thick, and it weighs 206 grams. The minute hand has the same shape as the hour hand but it’s much longer, so I guess it is sufficiently different to be ISO-6425-compliant from this point of view. The dial is framed by the bezel in black ceramic, which has very bold numerals. The automatic Powermatic 80.111 calibre provides 80 hours power reserve, and has a Nivachron balance spring which provides anti-magnetic qualities. The watch is on a stainless steel bracelet or a black rubber strap, depending on the dial colour, which comprises black, blue and turquoise. The watch costs €1,035. Read more and purchase on the Tissot website.
9. Hamilton Khaki Navy Frogman Titanium Auto H77805335
When this watch was introduced in 2016, Hamilton communicated that it was ISO 6425-compliant. It has 1,000 metres water resistance, and a case size of 46 mm. It is powered by the H-10 self-winding movement with 80 hours power reserve. Features include a crown protector, a helium valve, high-brightness SuperLumiNova, and an unusual rubber strap with a soft shark’s skin texture inside. This watch costs €1,395. Read more here, or visit the Hamilton website.
10. Sinn Model Diving Watch T1
German company Sinn dedicates great attention to its tool watches’ technical performance, and their diving watches comply with DIN standards 8310 and 8306, with certification by external agency DNV. The Sinn Diving Watch T1 has a 45mm titanium case with a water resistance of 1,000 metres, 100 bar. It is powered by the ETA 2892-A2 self-winding movement. It is available on the Sinn website at prices starting at €2,690.