Side by side

Fortis Marinemaster M-40vsSeiko Prospex Sea 1968 Heritage Diver's GMT Watch Limited Edition

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

At a glance

11 of 29 specs differ
Diameter
Marinemaster M-4040mm
Prospex Sea 1968 Heritage Diver's GMT Watch Limited Edition42mm
Power Reserve
Marinemaster M-4038h
Prospex Sea 1968 Heritage Diver's GMT Watch Limited Edition72h
Water Resistance
Marinemaster M-40300m
Prospex Sea 1968 Heritage Diver's GMT Watch Limited Edition300m
MSRP
Marinemaster M-40$3,520
Prospex Sea 1968 Heritage Diver's GMT Watch Limited Edition$1,750

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
$1,750

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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 1968 Heritage Diver's GMT Watch Limited Edition

The Seiko Prospex Sea 1968 Heritage Diver's GMT Watch Limited Edition is widely praised for its excellent quality and finishing relative to its price point, featuring a beautiful case, bracelet, and strong Lumibrite lume. Enthusiasts and reviewers highlight the comfortable 42mm case size and the distinctive 4 o'clock crown position. The watch is powered by the in-house 6R54 automatic movement, offering a 72-hour power reserve and rated accuracy of -5/+10 seconds per day, though one source notes the GMT function is secondary. Some find the 4:30 date window divisive, and the bezel clicks are described as quieter than expected. On balance, owners and reviewers rate the Seiko Prospex Sea 1968 Heritage Diver's GMT Watch Limited Edition highly for its refined design and strong value proposition.

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