Side by side

Fortis Marinemaster M-40vsSeiko 5KX

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
5KX
Seiko5KX
MSRP $350

At a glance

12 of 29 specs differ
Diameter
Marinemaster M-4040mm
5KX42.5mm
Power Reserve
Marinemaster M-4038h
5KX41h
Water Resistance
Marinemaster M-40300m
5KX100m
MSRP
Marinemaster M-40$3,520
5KX$350

Full specifications

Case

5 specs
Diameter
40mm
42.5mm
Thickness
13mm
13.4mm
Lug-to-Lug
46mm
Lug Width
21mm
22mm
Water Resistance
300m
100m

Crystal & Dial

3 specs
Crystal
Sapphire
Hardlex
Dial Color
Orange
Black
Lume
None
LumiBrite on hands and index(es)

Movement

3 specs
Caliber
Sellita SW220-1
4R36
Power Reserve
38h
41h
Jewels
26
24

Pricing

1 specs
MSRP
$3,520
$350

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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 5KX

Owners widely praise the Seiko 5 Sports SKX series for its strong lume and comfortable wearability, with many noting its compact feel due to a short lug-to-lug length. The NH36 movement's accuracy varies, with typical performance between +/-5 to 10 seconds per day, though some report better. A lack of screw-down crown and ISO certification are noted drawbacks for its water resistance. Some owners find the bracelet to be of cheaper construction with hollow links, and a few have reported quality control issues. The consensus is that the Seiko 5 Sports SKX series offers good value for its price, appealing to those who appreciate its tool-like nature and iconic lineage.

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