Side by side

Fortis Marinemaster M-40vsSeiko Prospex Sea

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
Prospex Sea
SeikoProspex Sea

At a glance

11 of 29 specs differ
Diameter
Marinemaster M-4040mm
Prospex Sea42mm
Power Reserve
Marinemaster M-4038h
Prospex Sea72h
Water Resistance
Marinemaster M-40300m
Prospex Sea300m
MSRP
Marinemaster M-40$3,520
Prospex Sea

Full specifications

Case

4 specs
Diameter
40mm
42mm
Thickness
13mm
13.3mm
Lug-to-Lug
48.6mm
Lug Width
21mm
20mm

Crystal & Dial

3 specs
AR Coating
Inner
Anti-reflective coating on inner surface
Dial Color
Orange
Black
Lume
None
LumiBrite on hands, index(es) and bezel

Movement

3 specs
Caliber
Sellita SW220-1
6R54
Power Reserve
38h
72h
Jewels
26
24

Pricing

1 specs
MSRP
$3,520

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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 Prospex Sea

Owners widely praise the Seiko Prospex Sea for its excellent value, solid build, and comfortable wearability, with specific mentions of its matte black dial, excellent lume, and cushion case that wears smaller than its dimensions suggest. The 4R36 movement is noted for hacking and hand-winding capabilities, and the bezel action is described as smooth and precise. Some owners find the watch to be a legitimate tool with a fair price, while others describe it as big, thick, and heavy, uncomfortable for smaller wrists, though this is subjective as one owner found the size perfect. The solar quartz movement is also highlighted as a collection-worthy feature. On balance, owners and reviewers rate the Seiko Prospex Sea highly for its exceptional value and comfortable, classic design.

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