Yes—the Certina DS Action Diver 40.5mm has the published credentials of a serious dive watch. The 2025 model is rated to 300 metres and certified to ISO 6425:2018. The black stainless-steel Powermatic 80 version, reference C048.407.18.051.01, was listed at £790 on Certina’s UK site at the time of publication. Its 40.5mm case, 14.1mm thickness and 48.3mm lug-to-lug reach make it a genuine mid-size diver on paper, rather than a small dress watch with dive styling.
What the DS Action Diver 40.5mm is
Certina announced the DS Action Diver 40.5mm on 29 April 2025 as a new mid-size addition to the DS Action family. The launch covered four steel and titanium configurations, all using ceramic bezels and matching dials. The range is intended to fill the space between the existing smaller and larger DS Action Diver cases.
The strongest evidence for its tool-watch status comes from the official specifications: 300m water resistance and ISO 6425:2018 certification. Those are materially different from simply printing “diver” on a dial.
Published specifications
| Specification | Certina DS Action Diver 40.5mm |
|---|---|
| Case diameter | 40.5mm |
| Case thickness | 14.1mm |
| Lug-to-lug | 48.3mm |
| Lug spacing | 20mm |
| Water resistance | 300m |
| Dive standard | ISO 6425:2018 certification |
| Crystal | Sapphire with one-side anti-reflective treatment |
| Bezel | Ceramic |
| Movement | Powermatic 80.611 automatic |
| Advertised power reserve | Up to 80 hours |
| Balance spring | Nivachron |
| Strap | Synthetic NATO with quick-release system |
| Buckle | 316L stainless steel |
| Weight | 110g for black steel reference C048.407.18.051.01 |
These are Certina’s published figures for the model and, where stated, the black steel reference. They should not be treated as independent timing, impact or water-pressure test results.
#1 Best Overall
- Case Size: 38 mm, Band Width: 13.00 mm, Case Thickness: 38.00 mm
- Automatic movement, Powermatic 80, Nivachron, Index dial type, Date
- Stainless steel bracelet, Double Locking Foldover Clasp
- Water-resistant up to 300 m / 990 ft: suitable for diving and/or snorkeling.
- 2 Year International Warranty
How the 40.5mm case should wear
The key ergonomic measurement is not diameter alone. At 48.3mm, the lug-to-lug length gives the case a relatively compact reach for a modern mechanical diver, while 14.1mm remains substantial because the watch is built for 300m service. The 20mm lug spacing also gives buyers a broad selection of replacement straps.
The 40.5mm model is positioned between the DS Action Diver’s 38mm and 43mm offerings, but the supplied product information does not establish the exact thickness or lug-to-lug figures for those two sizes. That means a precise wrist-size comparison would be guesswork. Buyers should compare lug-to-lug measurements, not diameter in isolation, before choosing among them.
Rank #2
- Case size: 40.50 mm: Band Width: 20.00 mm: Case Thickness: 14.10 mm
- Automatic , Powermatic 80, Nivachron, Date
- Band Type: Steel: Band Length: 179.64 mm
- Water-resistant up to 300 m / 990 ft: suitable for diving and/or snorkeling.
- 2 Year International Warranty
| Model size | What is established | What is not stated in the available product information |
|---|---|---|
| 38mm | It is another DS Action Diver size | Exact thickness and lug-to-lug reach |
| 40.5mm | 40.5mm diameter, 14.1mm thick, 48.3mm lug-to-lug | Independent wrist-wear measurements |
| 43mm | It is another DS Action Diver size | Exact thickness and lug-to-lug reach |
Movement and daily-use implications
The Powermatic 80.611 is an automatic Swiss Made movement with an advertised reserve of up to 80 hours. In practical terms, a fully wound watch can remain running through a weekend off the wrist, although actual autonomy varies with winding efficiency and use. The Nivachron balance spring is intended to improve resistance to magnetic fields, but no independent accuracy or magnetism test is provided here.
The cited black reference weighs 110g and uses a synthetic NATO strap with quick release. That combination avoids the greater mass of a steel bracelet and lets the wearer change straps without tools. Its 20mm lug spacing means any replacement NATO or two-piece strap must be sized accordingly.
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Rank #3
- Case Size: 12.20 mm, Band Width: 38.00 mm, Case Thickness: 38.00 mm
- Swiss Automatic movement, Titanium case, DATE, Grey band
- Band Type : Titanium, Band Length: 175mm
- Water-resistant Diver's watch 300m according to ISO 6425:2018
- 2 Year International Warranty
Materials and dive protection
- Sapphire crystal: more scratch-resistant than mineral crystal and treated with anti-reflective coating on one side.
- Ceramic bezel: a hard, scratch-resistant material commonly selected for dive-watch inserts.
- 300m rating: a substantial depth rating, backed by the stated ISO 6425:2018 certification.
- DS Concept Extreme Shock Resistance: Certina says this is the first model to use the new system.
In its 29 April 2025 press release, Certina stated: “This technology enables the timepiece to withstand g-forces so extreme that the testing equipment itself reached its limits during trials.” That is a manufacturer claim, not an independently published laboratory result, so it should be read as Certina’s description of its testing rather than a verified performance benchmark.
Price and the reference to buy
Certina’s official UK product page listed the black stainless-steel Powermatic 80 model, reference C048.407.18.051.01, at £790. The price is region-specific and can change with stock, currency and subsequent retail updates.
Rank #4
- Case Size: 38.00 mm, Band Width: 19, Case Thickness: 12.20 mm
- Automatic movement, Powermatic 80, Nivachron, Index dial type, Date
- Stainless steel bracelet, Double Locking Foldover Clasp
- Water-resistant up to 300 m / 990 ft: suitable for diving and/or snorkeling.
- 2 Year International Warranty
The collection contains several 40.5mm references. Case material, dial and bezel colour, and strap configuration can change the listed price, so “DS Action Diver 40.5mm” is not precise enough for a purchase decision. Match the full reference number to the seller’s listing and confirm that the seller is authorised in your country.
Best choice for a black steel configuration
Choose C048.407.18.051.01 if you want the black stainless-steel case and the published £790 UK configuration. It pairs the Powermatic 80.611 movement with the supplied synthetic NATO strap and 110g stated weight.
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Best Value
- Case size: 40.00 mm: Band Width: 20.00 mm: Case Thickness: 11.20 mm
- Quartz , Precidrive
- Band Type: Steel: Band Length: 179.05 mm
- Water-resistant up to 300 m / 990 ft: suitable for diving and/or snorkeling.
- 2 Year International Warranty
When to choose another 40.5mm reference
Select a different reference only after deciding whether titanium, another dial and bezel colour, or a different supplied strap matters more than matching the black steel specification. Do not assume that the £790 price or 110g weight applies to every 40.5mm variant.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.What is—and is not—established about the hands-on experience
The available official information establishes dimensions, materials, movement, rating and strap construction. It does not provide independent observations of bezel-click quality, crown action, clasp comfort, lume brightness, dial legibility in darkness, winding feel or measured daily accuracy. Those characteristics require a physical inspection or instrumented test and should not be inferred from the specification sheet.
Verdict
The Certina DS Action Diver 40.5mm is a serious dive watch by its published credentials: 300m water resistance, ISO 6425:2018 certification, sapphire crystal, ceramic bezel and an 80-hour Powermatic 80.611 movement. Its 40.5mm by 48.3mm footprint is the documented mid-size option, while the 14.1mm thickness reflects its substantial water rating. For UK buyers seeking the black steel version, C048.407.18.051.01 is the reference to check, with £790 as Certina’s listed price at the cited time.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
