Seiko Marinemaster 300 SLA021 Review After 2 Years: A Bargain Grand Seiko Or An Expensive Seiko?

The Seiko Marinemaster 300 SLA021 is based on one of Seiko's most iconic dive watch designs, the 6159. It is often compared to other tool dive watches such as the Tudor Pelagos, Sinn U1, and occasionally even the Omega Seamaster Ploprof. These are arguably the most professional dive watches offered by each brand.

However, is the MM300 worth buying in 2021, in the midst of all the competition, and after the new releases of the Seiko Captain Willard (SPB151), 62MAS (SPB143), and the Steelmaster (SPB185). I’ll answer this question as we take a look at the MM300 out in the sun and through the macro lens. I believe the answer to the main question is: yes the MM300 is still a one of a kind watch and great buy.

The Seiko MM300 stays true to the original by featuring a monobloc case which was made to keep helium out all together for saturation divers. This in turn created a very unique but heavy case. However, the case is a masterclass in case design because Seiko managed to make a watch that is physically big, into something that wears comfortably and much smaller than the numbers would suggest.

Alongside the beautiful case, the handset is wonderfully brushed and beveled to give the MM300 the look of a watch that is far more expensive. All in all Seiko has is offering a Grand Seiko level watch at a much lower price.


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TIME STAMPS:

The MM300 - 00:00
Dimensions and Specs - 03:39
Case - 04:35
Bezel - 06:40
Dial, Hands, and Indices - 07:54
Bracelet - 09:08
Negatives - 10:42
Should You Buy It In 2021? - 13:36
Thanks For Watching! - 15:23


DIMENSIONS:

Case width: 43.9mm
Lug width: 20mm
Bracelet at clasp: 18mm
Bracelet taper: 2mm
Lug to lug: 50.1mm
Bezel width: 42mm
Dial width: 29mm
Case thickness: 15.2mm
Midcase thickness: 9mm
Bezel height: 4.7mm
Crown diameter: 6.8mm
Crown height: 4.4mm
Weight: with bracelet (7.5 inch wrist): 210 grams
Weight: watch head: 120 grams
Water resistance: 300m
Crystal: flat sapphire
Movement: Grand Seiko 8L35


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