Side by side

Fortis Marinemaster M-40vsSeiko Monster

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
Monster
SeikoMonster
MSRP $550

At a glance

12 of 29 specs differ
Diameter
Marinemaster M-4040mm
Monster42.4mm
Power Reserve
Marinemaster M-4038h
Monster41h
Water Resistance
Marinemaster M-40300m
Monster200m
MSRP
Marinemaster M-40$3,520
Monster$550

Full specifications

Case

5 specs
Diameter
40mm
42.4mm
Thickness
13mm
13.4mm
Lug-to-Lug
49.4mm
Lug Width
21mm
20mm
Water Resistance
300m
200m

Crystal & Dial

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

Movement

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

Pricing

1 specs
MSRP
$3,520
$550

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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 Monster

Owners widely praise the Seiko Prospex Sea for its excellent value, robust build, and superb lume, with many noting its comfortable wearability. Reviewers consistently highlight its impressive finishing and classic dive watch design, often comparing it favorably to older models. Some owners find the size substantial, with one noting it as big, thick, and heavy on a 6.5-inch wrist, while others find it perfect. On balance, owners and reviewers rate the Seiko Prospex Sea highly for its exceptional value and robust, classic dive watch design.

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