Side by side

Spinnaker Bradner GMTvsSeiko Astron

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

Bradner GMT
SpinnakerBradner GMT
MSRP $299
Astron
SeikoAstron
MSRP $3,100

At a glance

14 of 29 specs differ
Diameter
Bradner GMT42mm
Astron44.1mm
Power Reserve
Bradner GMT40h
Astron40h
Water Resistance
Bradner GMT180m
Astron100m
MSRP
Bradner GMT$299
Astron$3,100

Full specifications

Case

6 specs
Category
GMT
Chronograph
Diameter
42mm
44.1mm
Thickness
15mm
14.4mm
Lug Width
22mm
14mm
Material
316L Stainless Steel
Titanium
Water Resistance
180m
100m

Crystal & Dial

4 specs
Crystal Shape
Flat
Curved
AR Coating
Inner
Super-clear coating
Dial Color
Brown
Black
Lume
None
LumiBrite on hands and index(es)

Movement

3 specs
Caliber
Seiko NH34A
5X83
Type
Automatic
Quartz
Jewels
25
14

Pricing

1 specs
MSRP
$299
$3,100

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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.

Spinnaker Bradner GMT

The Spinnaker Bradner GMT is praised for its awesome lume and comfortable wearability, with one owner noting the rubber strap is very comfortable and the beads of rice bracelet fits well on smaller wrists. Some find its 15mm thickness and bold colorway may not appeal to everyone, and one owner views it as more of a casual GMT with tool-watch styling than a diver. Overall, owners rate the Spinnaker Bradner GMT highly for its value and comfortable wearability.

Seiko Astron

Owners widely praise the Seiko Astron for its spectacular technology, self-sufficiency, and grab-and-go convenience, with one owner calling it the best watch they have ever had. Reviewers and owners highlight the detailed and well-managed dials, often with "Grand Seiko-esque" precision, and appreciate the comfortable, lightweight titanium construction. The solar-powered quartz movement with GPS time sync is a significant draw, offering accurate timekeeping. However, the price point of around €2250-€2400 is frequently cited as high for a quartz watch. Some owners note manual DST implementation, dependence on outdoor conditions or radio tower proximity for GPS sync, and sparse lume. One owner experienced the minute hand sitting slightly off and found the recessed buttons difficult to operate. Accuracy figures vary, with some reporting +/- 15 seconds per month without GPS, while others note autonomous quartz movement accuracy of up to 1/2 second per day.

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