Alpina Seastrong Diver Extreme Automatic dive watch
Starting from 1995 €The Alpina Seastrong Diver Extreme Automatic transplants the Extreme cushion case, born in the land-based Alpiner line, into the Geneva brand's dive watch universe. The result is a compact diver measuring 39 x 40.50 mm and 12.65 mm thick, water resistant to 300 metres, powered by the automatic AL-525 calibre built on a Sellita SW200 base. A signature triangular dial pattern, luminescent hands and hour markers, a date window at 6 o'clock and a unidirectional matte black ceramic bezel combine into a tool watch as credible underwater as it is everyday. Offered in five dial and strap versions between €1,995 and €2,295, it targets fans of measured, boldly styled Swiss divers.
Alpina Seastrong Diver Extreme Automatic dive watch
Alpina Watch International SA, based in Plan-les-Ouates near Geneva, passed the 140-year mark in 2023. The Swiss house has built its identity on watches designed for the outdoors, organised into clearly defined families: Alpiner for the mountains, Startimer for aviation, Seastrong for the sea. This division by use case explains the logic behind the Seastrong Diver Extreme Automatic, which stems from a deliberate crossover between two of the brand's universes.
The cushion case named Extreme had until now belonged to the land-based Alpiner line. In April 2024, Alpina brought it into its dive collection for the first time, with three versions: an anthracite dial with an integrated steel bracelet, a navy blue dial with matching rubber, and a black dial with an orange chapter ring and orange rubber. The integrated steel bracelet, designed in 2023 for the Extreme case, also made its debut in the Seastrong universe on this occasion.
The family grew at Geneva Watch Days in September 2025 with two executions joining the permanent collection: a sandblasted black dial and a grained khaki dial. Both receive an
Technical specifications Alpina Seastrong Diver Extreme Automatic
- Brand: Alpina
- Model: Seastrong Diver Extreme Automatic
- Reference: Depends on model
- Indicative price: From €1,995
- Movement: Automatic
- Calibre: AL-525 (Sellita SW200 base)
- Diameter: 39 x 40.50 mm
- Thickness: 12.65 mm
- Water resistance: 300 m / 30 ATM
- Materials: 316L stainless steel, black ceramic
- Crystal: Anti-reflective treated sapphire
- Dial: Anthracite, navy blue, black, black with orange chapter ring, or khaki
- Strap: Integrated 316L stainless steel or textured rubber
- Warranty: 2 years
The Alpina Seastrong Diver Extreme Automatic dive watch
The Seastrong Diver Extreme Automatic is first recognised by its silhouette. The Extreme cushion case, in 316L stainless steel, measures 39 x 40.50 mm and is 12.65 mm thick, dimensions that place it among compact, unisex divers. The surfaces alternate brushed and polished finishes, a combination that adds relief to the shape without compromising its technical character. The unidirectional matte black ceramic bezel, notched for grip, can be operated with gloves and absorbs light rather than reflecting it, which helps overall legibility. The dial carries Alpina's signature triangular pattern, with luminescent silver hands and hour markers and a date window at 6 o'clock, a position that preserves the display's symmetry.
Under the anti-reflective treated sapphire crystal, readability stays clear both in bright sunlight and at depth. The 300 m / 30 ATM water resistance goes well beyond the needs of recreational diving, and the brand describes this Seastrong as meeting the requirements of the ISO 6425 standard. The stated positioning is twofold: a tool watch credible underwater, yet measured enough to wear under a shirt cuff. That is the whole appeal of this cushion shape, shorter than a round case of apparently equivalent diameter, which sits flat on medium-sized wrists. Pricing ranges from €1,995 to €2,295 depending on the version chosen.
Five versions, one technical foundation
The collection now numbers five executions that share case, calibre and water resistance, differing only in dial and strap. Reference AL-525G3VE6B pairs an anthracite dial with the integrated 316L stainless steel bracelet measuring 174 mm, the only version to receive this bracelet designed for the Extreme case; it is also the most expensive, at €2,295. Next come two versions from the 2024 launch: a navy blue dial with matching rubber and a crown guard of the same shade, and a black dial with an orange chapter ring mounted on orange rubber, the most contrasted of the range. The last two, introduced at Geneva Watch Days in September 2025 and now part of the permanent collection, cultivate a different mood.
The sandblasted black dial and the khaki dial with a grained finish feature “old radium” Super-LumiNova with a patinated effect on the indexes, hands and seconds-hand counterweight, along with a red triangle on the seconds hand. The former leans towards vintage appeal, while the latter takes on a more tactical, outdoor character. Both are supplied on textured black rubber straps. Whatever the choice, the mechanics remain unchanged: an automatic AL-525 calibre, a stated 38-hour power reserve, and hours, minutes, seconds and date displays. All four rubber-strap versions are priced at €1,995.
Alpina Seastrong Diver Extreme Automatic dive watch: the cushion case underwater
Extreme cushion case in 316L stainless steel measuring 39 x 40.50 mm and 12.65 mm thick, unidirectional notched matte black ceramic bezel, anti-reflective treated sapphire crystal, screw-down crown and caseback, caseback engraved Seastrong: the Seastrong Diver Extreme Automatic brings together the attributes of a genuine diver in a compact format. The automatic AL-525 calibre, built on a Sellita SW200 base, beating at 28,800 vibrations per hour and fitted with 26 jewels, offers 38 hours of power reserve and displays hours, minutes, seconds and date at 6 o'clock. Water resistance reaches 300 metres. Five dial and strap versions are available, from €1,995 to €2,295, with a two-year international warranty.
Movement
The watch is powered by the AL-525 calibre, an automatic movement developed on a Sellita SW200 base. It beats at 28,800 vibrations per hour, carries 26 jewels and offers a 38-hour power reserve, enough autonomy to cover a night off the wrist, though tighter over a full weekend. The display sticks to the essentials of a diver: hours, minutes, seconds and date at 6 o'clock, a position that preserves the dial's balance. A proven architecture, easy to service through the Swiss watchmaking network.
Diameter and materials
The Extreme cushion case measures 39 x 40.50 mm and is 12.65 mm thick, in brushed and polished 316L stainless steel. It is topped with a notched unidirectional matte black ceramic bezel and protected by an anti-reflective treated sapphire crystal. The dial adopts the brand's signature triangular pattern, in anthracite, navy blue, black, black with orange chapter ring, or khaki depending on the reference, with luminescent silver hands and hour markers. The two most recent executions receive a patina-effect Super-LumiNova
Water resistance
The 300 m / 30 ATM water resistance comfortably covers scuba diving as well as repeated water sports use. It relies on a screw-down crown and a screw-down caseback engraved Seastrong, two elements that lock the case before immersion. The unidirectional notched bezel allows dive time to be tracked without risk of accidental misalignment, and the luminescence of the hands and hour markers ensures readability in darkness. Alpina describes this Seastrong as meeting the requirements of the ISO 6425 standard.
Accessories
Two mountings are offered depending on the version. The anthracite reference comes on an integrated 316L stainless steel bracelet measuring 174 mm, designed specifically for the Extreme case. The four other executions are delivered on textured rubber measuring 75 x 115 mm, in blue, orange or black depending on the dial chosen. In both cases, closure is secured by a deployant buckle with pushers, safer than a simple pin buckle on a wet wrist. Alpina does not detail the box contents.
Warranty
Alpina applies a two-year international warranty from the date of purchase, a commitment the Geneva house has upheld since the 1920s. It relies on the warranty certificate signed by the retailer, a document to keep since it governs coverage. The duration is not repeated on the product page itself, but appears in the conditions published by the brand. The service centre network then handles periodic servicing of the AL-525 calibre.
Alpina Seastrong Diver Extreme Automatic The pros
and cons
- Compact 39 mm cushion case
- Notched matte black ceramic bezel
- Swiss automatic AL-525 calibre
- Five dial versions available
- Claimed ISO 6425 compliance
- Power reserve limited to 38 hours
- Noticeable 12.65 mm thickness
- Steel bracelet limited to one version
- Divisive cushion shape
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Prices and technical specifications are subject to change. Content and photos are not contractual.
