Coming from Geneva, Switzerland, the Alpina Seastrong diver was first seen in the late 1960’s.
Back then it was known as ’10 Seastrong’.
It has been through a few changes over the years and this new iteration, which was released in 2016, replaces the out-going Alpina Extreme Diver.

A noticable feature of the Seastrong Diver 300 Automatic is the absense of a minute index which gives the dial a minimalist look.

If you do you prefer a more busy looking dial there is a range of other Seastrong Divers available though not all have automatic movement.

Black is a flattering colour as it makes everything look good. But not everyone likes black and Alpina have taken this into consideration offering four different colour bezel inserts – red, grey, blue and black.

Two options are available for the strap, an H-link bracelet or a rubber strap which comes colour matched to the bezel (except the red).


Stainless steel case of 44mm by 13mm thick. Screw-in crown @ 3 o’clock position.


Alpina AL-525 (modified Sellita SW200) with 26 jewels. It features Incabloc shock protection, a power reserve of 38 hours and 28,800 bph.


Dial is simple and minimalistic . Large luminous indices are used as hour markers. Small date window at 3’clock.


Uni-directional 120 click bezel has raised luminous markers.


Case size of the Alpina Seastrong Diver 300 is 44mm with a 22mm lug width for the strap. Thickness is a deceptive 13mm, looks thicker due in part to the oversize screw-in crown.

Although the stainless steel case is not ISO certified it is rated to 300 meters.

Surprisingly on this 300m diver is a see-thru case back. The screw down portion is stainless steel while the view port is sapphire crystal. This style of case back must add to the complications of achieving water resistance at depth.


Alpina produce several of their own movements, though the AL525 automatic caliber in the Seastrong is not one of them.

What it is, is a modified Sellita SW200. The custom black rotor is a dead give away that the SW200 has been ‘toyed’ with

The 26 jewel automatic movement has incabloc shock protection, hand-winding, hacking and a power reserve of 38 hours. 

Accuracy of the AL-525 is somewhat unknown, but we take a look at the base Sellita SW 200 with it’s -12 to +12 seconds/day. 

It would be fair to assume that the modified version fitted in to the Seastrong would have better accuracy and be closer to the high grade SW 200 with it’s -4 to +4 seconds/day.


A sapphire crystal with anti-reflective treatment adorns the face while a stainless bezel with segmented coin edging and uni-directional rotation gives edge protection to the crystal.

The bezel insert has raised luminous markers and comes in four colours, red, black, blue and grey.

Looking at the black dial, it has a simple un-cluttered look due in part to not having minute markers. Though there is small arabic numbers marking 5 minute intervals on a slightly raised and angled chapter ring.

Like on the bezel, raised capsule shaped markers index the hours. Except at the 12 o’clock position a triangle holds place (a nod to Alpina’s logo). All markers and the hands are luminous.

A small date window aligns with the 3 o’clock position.


  • Excellent build quality (…most people who have purchased or reviewed one have that same comment to make)


  • None

(The case at 44mm maybe a little big for smaller wrists)


Like everything, the Alpina Seastrong Diver 300 Automatic is not for everyone. At 44mm case diameter it will wear better on bigger wrists.

Also, many will probably find the missing minute markers diconcerting. Although, I do find it an easy to read dial.

As someone who is relatively hard on watches (due to work and sport environments) a ceramic bezel insert would prove harder wearing than the aluminium one. That said, a watch like this I would not wear in the engineering shop nor while riding cross country motorcycles.

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