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 $2,900

At a glance

16 of 29 specs differ
Diameter
Marinemaster M-4040mm
Astron GPS Solar 2025 Limited Edition43.4mm
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$2,900

Full specifications

Case

7 specs
Category
Diver
Chronograph
Diameter
40mm
43.4mm
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
$2,900

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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 lauded for its advanced satellite timekeeping and perpetual calendar functionality, offering global time and location updates via GPS signals. Owners appreciate its well-built titanium or steel case, often featuring a ceramic bezel, and the unique asymmetrical design inspired by the 1983 Seiko 7A28 6000. However, its substantial 47mm size and 16.5mm thickness are frequently noted as drawbacks, with some finding it wears large and is difficult to fit under shirt sleeves. The perpetual calendar is limited to displaying only the date, and GPS signal reception requires a clear view of the sky, posing challenges indoors. The watch is priced around $2,900 and is limited to 3,000 pieces. Overall, owners and reviewers value the Seiko Astron GPS Solar 2025 Limited Edition for its cutting-edge technology and distinctive design, despite its considerable dimensions.

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