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
MSRP $625

At a glance

12 of 29 specs differ
Diameter
Marinemaster M-4040mm
Prospex Sea43.8mm
Power Reserve
Marinemaster M-4038h
Prospex Sea41h
Water Resistance
Marinemaster M-40300m
Prospex Sea200m
MSRP
Marinemaster M-40$3,520
Prospex Sea$625

Full specifications

Case

5 specs
Diameter
40mm
43.8mm
Thickness
13mm
12.8mm
Lug-to-Lug
48.7mm
Lug Width
21mm
22mm
Water Resistance
300m
200m

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
4R35
Power Reserve
38h
41h
Jewels
26
23

Pricing

1 specs
MSRP
$3,520
$625

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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

The Seiko Prospex Sea is widely praised for its excellent value, solid build quality, and comfortable wearability, with many models featuring impressive lume and attractive dials. Owners and reviewers highlight the modern upgrades on classic designs, such as drilled lugs and reliable movements with hacking and hand-winding capabilities. Some models are noted for their refined case finishing and scratch resistance. Accuracy figures vary, with one owner reporting approximately 4 seconds fast per day, while others find the movements offer good performance for the price. Concerns raised by owners and reviewers include clasps that can feel generic or cheap, and lug widths that some find disproportionate to the case size on certain models. The thickness and weight of some Prospex Sea watches are also noted as substantial. The GMT function on specific models is considered secondary and difficult to read for true travel purposes.

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