Doxa SUB 300 COSC

The Doxa SUB 300 COSC upholds the Swiss brand’s reputation for robustness, peerless readability and impressive value for money. This particular model also features a COSC-certified movement. Angus Davies wore the watch for a week-long period and recounts his wearer experience.

Founded in 1889, Doxa has a rich history of making watches. Today, the brand is best known for producing divers’ watches.

This subaquatic journey commenced in 1967 with the release of the brand’s inaugural divers’ watch, the SUB 300. Unlike other divers’ watches of the time, available only to military or professional divers, the SUB 300 was also offered to the general public. Furthermore, the SUB 300 was developed in conjunction with diving-legend Jacques-Yves Cousteau, an association which imbued the SUB 300 with notable legitimacy.

Despite making the legendary SUB 300, for a number of years the brand slid into obscurity. However, everything changed in 2019 when Romeo F. Jenny was appointed the President of the Board of Directors of Walca Group and Jan Edöcs became a Board Member of the Walca Group and CEO of Doxa Watches.

Image – Jan Edöcs

With these two appointments, the brand soon returned to prominence with new-found vigour. I began receiving numerous press releases from Doxa and was invited to see the firm’s ‘novelties’ at Baselworld 2019. Suddenly, Doxa was in the news and for all the right reasons. Numerous magazines and websites were extolling the virtues of the brand’s products and retailers clamoured to be authorised stockists.

In the last 12 months, I have requested samples of the brand’s watches and evaluated them over a number of days. My findings have always been the same. The brand’s timepieces are well-made, highly legible and represent excellent value for money. Indeed, I have yet to be disappointed by any Doxa I have had the good fortune to wear.

Recently, I wore a Doxa SUB 300 COSC for a week-long period and recorded my observations to paper. I refer to my experience herein, however, firstly I wish to make reference to a recent conversation with Jan Edöcs, the CEO of Doxa.

In conversation with Jan Edöcs

Prior to chatting to Jan, I did not know that Doxa Watches was a sister company of Walca Group. This latter company was founded in 1976 and is a leading maker of private label watches. It offers an array of services from design, development, prototyping and manufacturing. Its repertoire of skills makes it an obvious choice for many companies, even large brands, wishing to outsource the making of certain models.

With the combined purchasing power of Walca and Doxa, Jan Edöcs is able to procure components at reasonable cost, allowing Doxa to sell impressive products at accessible prices. Moreover, Walca Group has set in place high standards of quality control and after sales care in order to meet the needs of its corporate clients. This infrastructure is also utilised by Doxa.

Doxa SUB 300 Stainless Steel COSC

When chatting to Jan, I enquired whether the company planned to offer new complications, such as tourbillons, in the future. His answer was unequivocal, ‘Doxa stays in the water’. He has chosen to leave different market segments to others, preferring to focus on what the company is best known for, namely, divers’ watches.

The dial

The Doxa SUB 300 COSC is available in a plethora of dial and strap configurations. Dial hues include orange, silver, black, navy, yellow and turquoise. The model is offered on a stainless steel bracelet or a colour coordinated rubber strap. My press loan was supplied with a black dial and a matching rubber strap.

Doxa SUB 300 COSC

Interestingly, in the 1960s Doxa personnel evaluated the underwater visibility of different dial colours by venturing into the murky waters of Lake Neuchâtel, close to the brand’s Biel/Bienne headquarters. As Jan explained to me, ‘it wasn’t the Maldives, it would have been very dark down there. However, orange proved the best colour for visibility.’

Doxa SUB 300 Stainless Steel COSC

Although I would have preferred to evaluate the yellow dial option, the black dial proved a very versatile colour, matching virtually all garments. And that brings me to my first point. Few owners will ever subject this watch to the harsh rigours of subaquatic exploration. Indeed, most wearers will probably select the Doxa SUB 300 COSC because of its appearance, robustness and suitability for swimming or showering. I freely admit that I subscribe to this latter group, however, the virtues of a divers’ watch on terra firma are equally valid.

Similar to the 1967 original, the minute hand is plump, dominating the dialscape. This is eminently sensible as minutes have greater significance when diving. Where the minute hand is presented in orange, the hour and central sweep seconds hands are depicted in white. The indexes are a simple baton design, sidestepping potential clutter. Both the hands and indexes feature luminescent detail, augmenting legibility in restricted light conditions. A date indication is positioned at 3 o’clock.

The sapphire crystal is of the glass box variety. While I witnessed some distortion of the indexes when viewed from the side, the watch proved eminently readable when viewed directly from the front. This model is endowed with a unidirectional bezel as divers’ watch convention dictates. The bezel is comprised of two rings, the inner ring displays the dive time in minutes and the outer ring indicates the dive depth in metres.

The case

The Doxa SUB 300 COSC is housed in a stainless steel case measuring 42.5mm x 45mm with a height of 13.4mm. The model blends a circular dial and bezel with a tonneau shaped case, delivering a handsome interplay of forms.

Doxa SUB 300 COSC

The strap is integrated, mitigating the overall length of the case and making the watch ‘wear smaller’ than the specified dimensions would suggest. The crown is located within a recess set in the caseband thereby reducing the risk of impact damage harming the winding stem. As convention dictates, this divers’ watch features a solid caseback.

Doxa has paid particular attention to the smallest details. For example, the vertical flank of the case is highly polished, delivering a becoming contrast with the satin-brushed surfaces. Furthermore, the rubber strap fitted to my press loan was paired with a high quality folding clasp. This clasp is equipped with two pushpieces, one to open the clasp and a second to adjust an extension piece. Personally, I found this latter facility very useful when warm days necessitated loosening the strap just a smidgen.

Doxa SUB 300 COSC


Appraising the habillage of this Doxa, everything feels solidly built, free of sharpness and impeccably refined. Indeed, this level of quality would normally attract a higher asking price.

The movement

The Swiss firm has equipped the Doxa SUB 300 COSC with the tried and trusted ETA 2824-2 calibre. This self-winding movement is extensively used within the watch industry and delivers precision and reliability as well as proving affordable. While this watch does not purport to be the last word in high horology, it ably fulfils the needs of most wearers.

Beyond its known reliability, the ETA 2824-2 calibre is simple to repair and service, mitigating on-going running costs.

Furthermore, the Doxa SUB 300 COSC is a certified chronometer. By subjecting its models for COSC certification, Doxa has incurred additional expense, an aspect which has to be recouped in the price of the model. However, the certification does afford the buyer with independent peace of mind when it comes to precision.

When a mechanical movement is submitted for COSC certification, it is evaluated over a 15 day period. The movement is tested at different temperatures and in different positions. The rate of the movement is checked under these different conditions and must comply with the stated minimum requirements of COSC.

The balance has a frequency of 28,800 vph (4Hz) and the rate is regulated using an ETACHRON system. Assuming the watch is fully wound, it will run autonomously for 42 hours. The movement features 25 jewels.

Closing remarks

Shortly after receiving the Doxa SUB 300 COSC, it soon looked at home on my wrist. It proved comfortable to wear, simple to read and performed flawlessly while in my care. The rubber strap and folding clasp looked superb and the extension piece was a welcome feature. When I chatted to Jan, he repeatedly talked about ‘functionality’ and when handling the watch, this characteristic was palpable. In fact, it is obvious that Doxa has made this timepiece as practical and user-friendly as possible.


Despite having a water resistance of 300 metres, the Doxa SUB 300 COSC will seldom be tested to its full potential. However, while I may be a ‘desk diver’, this model ably fulfils my requirements. Its many attributes are equally valid on dry land, providing a strong argument for acquisition. Moreover, with a vast choice of dial colours to choose from and super-keen pricing, my love of Doxa watches shows no signs of abating any time soon.

Doxa SUB 300 Stainless Steel COSC

Further reading

Technical specification

  • Model: Doxa SUB 300 COSC Sharkhunter
  • Reference: 821.10.101.20
  • Case: Stainless steel; dimensions 42.50 mm x 45.00 mm; height 13.4 mm; water resistance 30ATM (300 metres); sapphire crystal to front and solid case back
  • Functions: Hours; minutes; central sweep seconds; date
  • Movement: ETA 2824-2; self-winding movement; frequency 28,800 VpH (4Hz); 25 jewels; power reserve 42 hours
  • Strap: Black rubber strap with steel folding clasp and diver’s extension
  • Price: £2350 (RRP as at 4.9.2020)

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