The Alpina Seastrong Diver Extreme Automatic is a compact steel diver that pairs the angular, cushion-shaped case of Alpina’s Extreme design with the Seastrong line’s dive-watch role. The 2024 launch model measures 39 mm across, offers a stated 300 m water resistance, and uses an automatic AL-525 movement. Its original colors were black, navy blue, and grey; later black, khaki, and limited-edition turquoise versions expanded the family.
What is the Alpina Seastrong Diver Extreme Automatic?
Introduced in 2024, the watch brings together two parts of Alpina’s catalog: the cushion-shaped case associated with the Alpiner Extreme and the Seastrong family’s dive-watch specifications. Its compact footprint and sharply defined case give it a different look from a conventional round diver, while a rotating timing bezel, screw-down crown, and 300 m stated water resistance establish its tool-watch credentials.
The original launch collection had three dial-and-strap combinations. Later releases added new colors and a limited edition, so “Seastrong Diver Extreme Automatic” now describes a family rather than one fixed configuration.
How big is the case, and what are its dive-watch features?
Monochrome Watches reported the 2024 launch model’s stainless-steel case at 39 mm in diameter, 40.4 mm long, and 12.65 mm thick. Those dimensions describe a compact diver by contemporary standards, though wrist fit also depends on the case shape and strap or bracelet.
#1 Best Overall
- The Seastrong Heritage model is inspired by the 1960’s professional diver design, a beautiful re-issue of this historic model. This timepiece features an automatic movement with a 60-minute internal rotating bezel. It also has a textured rubber strap, vintage white and black dial, screw down crown and an engraved caseback to protect the movement from everyday elements.
- 300M water resistant with uni-directional turning 60m diving bezel
- AL-525 Caliber - Automatic Self-wind Movement, 26 jewels, 38 Hours Power Reserve
- 42mm Case Diameter with Polished Stainless Steel Case
- Scratch Resistant Sapphire Crystal
- Case: Three-part stainless steel, with brushed surfaces and polished bevels, according to Monochrome’s 2024 launch report.
- Bezel: Unidirectional rotating bezel with a matte ceramic insert.
- Crown and caseback: Both screw down; the crown has a rubber grip.
- Crystal: Anti-reflective sapphire.
- Water resistance: 300 m, as reported for the launch model.
Monochrome also reported that the model complies with ISO 6425, the standard for divers’ watches. That compliance statement is attributed to the publication; it should not be treated as an independently verified certification here.
What movement does it use?
The AL-525 is an automatic movement based on Sellita’s SW200-1, according to Monochrome’s 2024 report. It has 26 jewels, runs at 28,800 vibrations per hour, and provides a reported 38-hour power reserve. The display comprises hours, minutes, central seconds, and a date aperture at six o’clock. The available material does not document chronometer certification.
Rank #2
- The Seastrong Diver Extreme Automatic is housed in a 39 x 40.50mm steele case and features three central hand-polished hands that sit at the heart of a dial textured with Alpina's iconic triangular emblem, punctuated by a date window at 6 o'clock.
- For maximum readability, both the hours and minutes hands and the hour markers have been coated with luminous material and the date window features black figures on a white background.
- WR to 300m, and comes on a bright orange rubber strap.
How do the black, blue, grey, and khaki versions differ?
The main differences documented across the range are dial color and finish, lume treatment, strap or bracelet, reference number, and edition status. The sources do not establish a difference in core movement or water resistance among these versions.
| Version | Reference | Dial and details | Strap or bracelet | Price reported at publication |
|---|---|---|---|---|
| Original black (2024 launch) | Not stated by Monochrome Watches | Black dial with embossed triangular pattern, applied markers, luminous material, partially openworked hands, and date at six | Matching textured rubber strap | CHF 1,995 for rubber-strap versions, Monochrome Watches, 12 April 2024 |
| Original navy blue (2024 launch) | Not stated by Monochrome Watches | Navy dial with embossed triangular pattern, applied markers, luminous material, partially openworked hands, and date at six | Matching textured rubber strap | CHF 1,995 for rubber-strap versions, Monochrome Watches, 12 April 2024 |
| Original grey (2024 launch) | Not stated by Monochrome Watches | Grey dial with embossed triangular pattern, applied markers, luminous material, partially openworked hands, and date at six | Integrated steel bracelet | Not stated in the cited launch report |
| Later black | AL-525B3VE6 | Black dial; aged-look “Old Radium” Super-LumiNova and black ceramic bezel insert | Textured black rubber strap | €1,995, Fratello Watches, 16 September 2025 |
| Later khaki | AL-525K3VE6 | Khaki dial; aged-look “Old Radium” Super-LumiNova and black ceramic bezel insert | Textured black rubber strap | €1,995, Fratello Watches, 16 September 2025 |
| Route du Rhum limited edition | AL-525T3VE6 | Turquoise dial; 300 m water resistance reported | Not stated in the cited coverage | $2,295 in U.S. coverage by Hodinkee in 2026 |
The original launch dial design used an embossed triangular pattern, applied markers, luminous material, partially openworked hour and minute hands, and a date window at six. Fratello’s later black and khaki references use “Old Radium” Super-LumiNova, a warmer aged-look lume treatment. Hodinkee’s 2026 coverage identifies the turquoise Route du Rhum model as a 313-piece limited edition; it is a later addition, not one of the original three colors.
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- Hour, Minute, Second, Date
- Anti-Reflective Sapphire Crystal
- Black Rubber Strap
- 300MM Water Resistant
Is the Alpina Seastrong Diver Extreme Automatic water resistant to 300 metres?
The 2024 launch model is reported as water resistant to 300 m. Fratello reported the same rating for the later black and khaki references, and Hodinkee reported it for the Route du Rhum edition. The available source coverage does not establish a difference in rating among these versions. Water resistance is a specification, not a guarantee that a watch remains safe for diving indefinitely; follow Alpina’s care guidance and have seals checked as appropriate before underwater use.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.How much does it cost?
The cited prices are tied to specific publication dates, regions, and versions, not verified current prices. Monochrome reported a CHF 1,995 launch price for the 2024 rubber-strap versions. Fratello reported €1,995 for the black and khaki references in 2025. Hodinkee reported a U.S. price of $2,295 for the 313-piece Route du Rhum limited edition in 2026. These figures are not directly comparable across currencies, markets, or release dates, and current official pricing and stock are not established here.
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- Hour, Minute, Second, Date
- Anti-Reflective Sapphire Crystal
- Black Rubber Strap
- 300MM Water Resistant
If you are checking a listing, match the reference to the version you want: AL-525B3VE6 for the later black model, AL-525K3VE6 for the later khaki model, and AL-525T3VE6 for the Route du Rhum limited edition. Confirm the seller, regional price, and availability directly before buying.
Quick Recap
Best Value
- Water-resistant to 300M, this 42mm Seastrong Diver 300 Heritage Automatic with steel case lets you measure your immersion time in hours, minutes and seconds. Its black lacquered sunray-brushed dial features gold plated luminescent hands, making it easy to read, even in the low light of the deep sea. Featuring a modern automatic caliber with 38 hours power reserve and an anti-scratch sapphire glass. Comes with two straps, one in brown calfskin leather and the other in beige topstitched rubber.
- Hours, Minutes, Seconds
- Silver-Tone Stainless Steel
- Anti-Reflective Sapphire Crystal
- 30 Meters and 3 Year Limited Warranty
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.
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