Side by side

Fortis Marinemaster M-40vsSeiko Astron GPS Solar 2025 Limited Edition

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 GPS Solar 2025 Limited Edition
SeikoAstron GPS Solar 2025 Limited Edition
MSRP $2,600

At a glance

15 of 29 specs differ
Diameter
Marinemaster M-4040mm
Astron GPS Solar 2025 Limited Edition42mm
Power Reserve
Marinemaster M-4038h
Astron GPS Solar 2025 Limited Edition40h
Water Resistance
Marinemaster M-40300m
Astron GPS Solar 2025 Limited Edition100m
MSRP
Marinemaster M-40$3,520
Astron GPS Solar 2025 Limited Edition$2,600

Full specifications

Case

7 specs
Category
Diver
GMT
Diameter
40mm
42mm
Thickness
13mm
12mm
Lug-to-Lug
47.9mm
Lug Width
21mm
14mm
Material
Stainless Steel
Titanium
Water Resistance
300m
100m

Crystal & Dial

3 specs
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
3X62
Type
Automatic
Quartz
Power Reserve
38h
40h
Jewels
26
10

Pricing

1 specs
MSRP
$3,520
$2,600

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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.

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 GPS Solar 2025 Limited Edition

The Seiko Astron GPS Solar 2025 Limited Edition is widely praised for its advanced GPS time and date adjustment capabilities, powered by light to eliminate battery changes. Owners and reviewers highlight its impressive accuracy and the convenience of automatic time zone updates, with some specifically commending the wearability of the 39mm size and its clean, simple design. However, reception of the GPS signal requires an unobstructed view of the sky, and manual time zone adjustments are necessary for Daylight Saving Time on some variants. One owner notes a slight imperfection in chapter ring alignment on the 39mm model. On balance, owners and reviewers rate the Seiko Astron GPS Solar 2025 Limited Edition highly for its satellite-powered timekeeping and improved wearability in the 39mm configuration.

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