Side by side

Formex Reef GMTvsSinn U18

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

Reef GMT
FormexReef GMT
MSRP $2,235
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.

Formex Reef GMT

The Formex Reef GMT is widely praised for its unique porthole case shape, COSC-certified Sellita SW330-2 movement with good finishing, and comfortable quick-release bracelet with on-the-fly micro-adjustment. Reviewers note its robust construction, impressive specifications, and strong value proposition, with a slim 11.4mm profile accommodating 300m water resistance and an exhibition caseback. However, owners widely report the 53mm lug-to-lug span with male endlinks makes it too large for smaller wrists. Some find the bezel action stiff and potentially slippery, and a reviewer desired sharper finishing and edges, deeming the aesthetic too modernist. The GMT variant sacrifices a timing bezel unless swapped, and one owner notes sharp edges on the crown and crown guard. Overall, owners and reviewers highly rate the Formex Reef GMT for its exceptional value and well-executed features, particularly its bracelet system and COSC-certified movement.

From video reviewers

The watch features a COSC-certified SW330-2 GMT movement, which is visible through a sapphire crystal display case back and beautifully decorated. The watch's water-resistance of up to 300m/1000ft is a notable feature. The 42mm diameter may be too large for smaller wrists.

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
Reef GMT42mm
U1844mm
Power Reserve
Reef GMT56h
U1842h
Water Resistance
Reef GMT300m
U182,000m
MSRP
Reef GMT$2,235
U18$3,488

Full specifications

Case

8 specs
Category
GMT
Diver
Diameter
42mm
44mm
Thickness
11.4mm
15.5mm
Lug-to-Lug
47mm
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
Indices
Applied
Lume
Super-LumiNova
None

Movement

2 specs
Caliber
Sellita SW330-2
SW300-1
Power Reserve
56h
42h

Pricing

1 specs
MSRP
$2,235
$3,488
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