Side by side

Formex Reef 39.5 mmvsSeiko Prospex Marinemaster Seiko Diver’s Watch 60th Anniversary Limited Edition

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

At a glance

13 of 29 specs differ
Diameter
Reef 39.5 mm39.5mm
Prospex Marinemaster Seiko Diver’s Watch 60th Anniversary Limited Edition45.4mm
Power Reserve
Reef 39.5 mm56h
Prospex Marinemaster Seiko Diver’s Watch 60th Anniversary Limited Edition72h
Water Resistance
Reef 39.5 mm300m
Prospex Marinemaster Seiko Diver’s Watch 60th Anniversary Limited Edition600m
MSRP
Reef 39.5 mm$2,230
Prospex Marinemaster Seiko Diver’s Watch 60th Anniversary Limited Edition$4,600

Full specifications

Case

5 specs
Diameter
39.5mm
45.4mm
Thickness
11mm
16mm
Lug-to-Lug
45.5mm
50.4mm
Material
Stainless Steel
Titanium
Water Resistance
300m
600m

Crystal & Dial

4 specs
Crystal Shape
Flat
Curved
AR Coating
Inner
Anti-reflective coating on inner surface
Dial Color
Bahama Blue
Black
Lume
Super-LumiNova
LumiBrite on hands, index(es) and bezel

Movement

3 specs
Caliber
Sellita SW300-1
8L45
Power Reserve
56h
72h
Jewels
25
35

Pricing

1 specs
MSRP
$2,230
$4,600

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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.

Seiko Prospex Marinemaster Seiko Diver’s Watch 60th Anniversary Limited Edition

Owners widely praise the Prospex Marinemaster Seiko Diver’s Watch 60th Anniversary Limited Edition's titanium monobloc case construction and the dial's blue gradient finish. Some owners find the 45.4mm diameter and 16mm thickness too large, noting a poor dial-to-bezel ratio and excessive text on the dial. The 8L45 movement offers a 72-hour power reserve, with reported accuracy ranging from +10/-5 seconds per day to +25/-15 seconds per day. On balance, owners appreciate the watch's tool watch vibe and unique dial construction, despite some reservations about its size and price.

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