Side by side

Marathon GSAR (Government Search & Rescue) Diver's AutomaticvsTudor Black Bay One 31

The numbers, the dial colors, the calibers — laid out so you can stop flipping between tabs.

GSAR (Government Search & Rescue) Diver's Automatic
MarathonGSAR (Government Search & Rescue) Diver's Automatic
MSRP $2,100
Black Bay One 31
TudorBlack Bay One 31
MSRP $4,600

At a glance

11 of 29 specs differ
Diameter
GSAR (Government Search & Rescue) Diver's Automatic41mm
Black Bay One 3131mm
Power Reserve
GSAR (Government Search & Rescue) Diver's Automatic40h
Black Bay One 3150h
Water Resistance
GSAR (Government Search & Rescue) Diver's Automatic300m
Black Bay One 31100m
MSRP
GSAR (Government Search & Rescue) Diver's Automatic$2,100
Black Bay One 31$4,600

Full specifications

Case

8 specs
Diameter
41mm
31mm
Thickness
14mm
9.5mm
Lug-to-Lug
48mm
46mm
Lug Width
20mm
17mm
Material
316L Stainless Steel
Stainless Steel
Finish
Brushed and polished
Polished + Satin
Water Resistance
300m
100m
Caseback
Solid
Solid screw-down

Movement

2 specs
Caliber
Sellita SW200-1
MT5201
Power Reserve
40h
50h

Pricing

1 specs
MSRP
$2,100
$4,600

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What people say

Owners + reviewers, side by side

Synthesized for each watch independently from owner discussions, enthusiast forums, written reviews, and video reviewers.

Marathon GSAR (Government Search & Rescue) Diver's Automatic

The Marathon GSAR (Government Search & Rescue) Diver's Automatic is widely praised for its legibility, comfort, and exceptional tritium illumination, with reviewers highlighting its utilitarian, military-equipment feel and a 41mm case size considered ideal. Owners appreciate its grippy bezel and the 300 meters of water resistance provided by the screw-down crown, deeming it a solid value for a Swiss-made tool watch. Some owners report quality control issues, with one user needing to warranty two watches, and another notes the GSAR wears taller than other models, leading to occasional bumping. The reliable ETA 2824-A2 movement is a consistent feature. Overall, owners and reviewers rate the Marathon GSAR (Government Search & Rescue) Diver's Automatic highly for its bright tritium lume and robust, no-nonsense tool watch design.

Tudor Black Bay One 31

Owners widely report the Tudor Black Bay One 31's polished case and bracelet scratch easily, though its wearability under gloves and robust movement are praised. Some desire more micro-adjustment options on the clasp, and a lack of contrast between the silver dial and hands is noted. The 31mm size may be a consideration for daily wear due to its 50-hour power reserve. On balance, owners and reviewers appreciate the Tudor Black Bay One 31 for its comfortable wearability and robust movement, despite concerns about case scratching and clasp adjustability.

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