Side by side

Fortis Marinemaster M-40vsSeiko Astron

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

Marinemaster M-40
FortisMarinemaster M-40
MSRP $3,520
Astron
SeikoAstron
MSRP $2,700

At a glance

16 of 29 specs differ
Diameter
Marinemaster M-4040mm
Astron43.3mm
Power Reserve
Marinemaster M-4038h
Astron40h
Water Resistance
Marinemaster M-40300m
Astron100m
MSRP
Marinemaster M-40$3,520
Astron$2,700

Full specifications

Case

7 specs
Category
Diver
Chronograph
Diameter
40mm
43.3mm
Thickness
13mm
13.4mm
Lug-to-Lug
49.5mm
Lug Width
21mm
14mm
Material
Stainless Steel
Titanium
Water Resistance
300m
100m

Crystal & Dial

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

Movement

4 specs
Caliber
Sellita SW220-1
5X83
Type
Automatic
Quartz
Power Reserve
38h
40h
Jewels
26
14

Pricing

1 specs
MSRP
$3,520
$2,700

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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.

Fortis Marinemaster M-40

Owners praise the Fortis Amber Orange for its gorgeous appearance and strong wrist presence, noting its crazy lume and 70-hour power reserve. The Doxa SUB 300T, described as having a superb, eccentric design with a highly legible dial and functional no-decompression bezel, uses an ETA 2824-2 movement. However, the SUB 300T's 42.5mm case wears large and its 14mm thickness is not ideal for dress shirts, though it boasts 1,200m water resistance. On balance, owners appreciate the Fortis Amber Orange for its striking aesthetics and impressive lume.

Seiko Astron

The Seiko Astron is widely praised for its advanced timekeeping technology, including GPS and radio wave synchronization, offering grab-and-go convenience and exceptional accuracy, with some users reporting +/- 15 seconds per month or even 1/2 second per day for its autonomous quartz movement. Owners appreciate its well-finished titanium cases and bracelets, detailed dials with high-contrast markers, and lightweight, comfortable wearability. However, some find the price point of around $2,000 to $2,400 expensive, noting that GPS sync works best outdoors and that certain models lack screw-down casebacks, impacting water resistance. The lume is described as sparse on some models, and recessed buttons require tools to operate. Overall, owners and reviewers rate the Seiko Astron highly for its cutting-edge technology and comfortable, well-finished design, with the value proposition becoming more compelling when models are found at a discount.

From video reviewers

The watch's automatic time zone adjustment via GPS is a notable feature. The watch's solar-powered charging system can take up to 6 months to fully charge, which may not be ideal for users who need a quick power boost.

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