Seiko Prospex Marinemaster 300

Seiko Prospex Marinemaster 300

Seiko Prospex Marinemaster 300 (ref. SLA073), 43.4 mm steel case, 15.9 mm high, automatic movement (8L35), 300 m water resistance. List price $3,600 to $3,800.

Specifications

Brand
Seiko
Reference
SLA073
Style
Diver
Case diameter
43.4 mm
Thickness
15.9 mm
Case material
Steel
Crystal
Sapphire
Movement
Automatic (8L35)
Power reserve
50 hours
Complications
date, rotating bezel
Water resistance
300 m
Strap or bracelet
Metal
Released
2024
List price
$3,600 to $3,800

Built for divers, not for cuffs

By Kenji Watanabe, Osaka ยท

15.9 mm. I read that number twice. The Marinemaster 300 has always been thick, and the SLA073 keeps the tradition along with the rest of the lineage that goes back to Seiko's 1968 300 m professional diver.

The rest is serious equipment: 43.4 mm steel case, sapphire, solid back, 300 m, black dial, date, steel bracelet, and the 8L35 automatic with 50 hours. The 8L35 is closely related to a Grand Seiko base movement, built without the decoration, which is a fair way to spend money on a tool watch.

My doubts. 50 hours is modest next to the 70 and 72 hours of the cheaper Prospex divers, the SPB453 above all. 3,600 to 3,800 dollars puts it in the same conversation as a Tudor Black Bay, which has a stronger bracelet and resale. And this case will never go under a shirt cuff. It will barely go under a winter coat sleeve.

For the Seiko diver collector who wants the top of the Prospex line, and who actually spends time near water, I understand it completely. For an office worker on the Midosuji line, I would buy the SPB453 and keep the change.

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