Side by side

Formex Reef 39.5 mmvsSpinnaker Dumas GMT

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

Reef 39.5 mm
FormexReef 39.5 mm
MSRP $2,230
Dumas GMT
SpinnakerDumas GMT
MSRP $399

At a glance

10 of 29 specs differ
Diameter
Reef 39.5 mm39.5mm
Dumas GMT44mm
Power Reserve
Reef 39.5 mm56h
Dumas GMT40h
Water Resistance
Reef 39.5 mm300m
Dumas GMT300m
MSRP
Reef 39.5 mm$2,230
Dumas GMT$399

Full specifications

Case

5 specs
Category
Diver
GMT
Diameter
39.5mm
44mm
Thickness
11mm
15mm
Lug-to-Lug
45.5mm
48mm
Material
Stainless Steel
316L Stainless Steel

Crystal & Dial

2 specs
Dial Color
Bahama Blue
Blue
Lume
Super-LumiNova
None

Movement

2 specs
Caliber
Sellita SW300-1
Seiko NH34A
Power Reserve
56h
40h

Pricing

1 specs
MSRP
$2,230
$399

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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.

Formex Reef 39.5 mm

The Formex Reef 39.5 mm is widely praised for its refined finishing, comfortable and well-proportioned case design, and impressive specifications for its price point, including COSC-certified Sellita SW300-1 movement and 300m water resistance. Owners and reviewers highlight the tool-less micro-adjust clasp and quick-release spring bars as practical features. Some reviewers note that the 22mm lug width feels slightly disproportionate to the smaller case, and the bracelet could benefit from more taper, though this is a point of contention for some owners who value the overall package. A prototype crown protrusion issue is noted as being addressed for production. On balance, owners and reviewers rate the Formex Reef 39.5 mm highly for its excellent value and well-executed design.

Spinnaker Dumas GMT

Owners praise the Spinnaker Dumas GMT's satisfying lume, including on the crown, and good finishing, with one owner finding it wears well on a 17cm wrist. The watch features a Seiko NH34A GMT movement and a blue gradient dial. Reviewers note its 44mm diameter and 209g weight on the bracelet make it unsuitable for smaller wrists.

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