Side by side

Fortis Marinemaster M-40vsSinn U18

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
U18
SinnU18
MSRP $3,488
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.

Sinn U18

The Sinn U18 is praised for its unique deep blue/green dial with three-dimensional oxygen bubbles that change with light, and its comfortable, easily adjustable bracelet. Owners find the watch stunning and a piece of history, appreciating the refined hands. The Sinn U18 features a 44mm, 15.5mm thick case made from German submarine steel, offering a 2000-meter dive specification and Sinn's Ar-Dehumidifying technology, powered by a Sellita SW300-1 movement. The case thickness is apparent, and the watch comes as a complete set with box and papers for $3,000-$3,680. On balance, owners and reviewers rate the Sinn U18 highly for its striking dial and robust build.

At a glance

15 of 29 specs differ
Diameter
Marinemaster M-4040mm
U1844mm
Power Reserve
Marinemaster M-4038h
U1842h
Water Resistance
Marinemaster M-40300m
U182,000m
MSRP
Marinemaster M-40$3,520
U18$3,488

Full specifications

Case

7 specs
Diameter
40mm
44mm
Thickness
13mm
15.5mm
Lug Width
21mm
22mm
Material
Stainless Steel
high-strength
Finish
Brushed and polished
Water Resistance
300m
2000m
Caseback
Solid

Crystal & Dial

4 specs
Crystal Shape
Flat
AR Coating
Inner
Dial Color
Orange
Black
Indices
Applied

Movement

3 specs
Caliber
Sellita SW220-1
SW300-1
Power Reserve
38h
42h
Jewels
26
25

Pricing

1 specs
MSRP
$3,520
$3,488
Keep exploring

More watches worth a look

Matched to the watches above on size, movement, style and price — microbrands first. Open any one to dig in.

Follow this matchup

Get a note when Fortis Marinemaster M-40 vs Sinn U18 gets more votes, a community discussion, or a price drop. No account needed.

Adjacent matchups

People also compared

Comparisons nearby in the catalog — alternatives to the watches above paired against the matchup.