Side by side

Seiko Prospex Marinemaster Marinemaster 1968 Heritage Diver's WatchvsFormex Reef 39.5 mm

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

12 of 29 specs differ
Diameter
Prospex Marinemaster Marinemaster 1968 Heritage Diver's Watch42.6mm
Reef 39.5 mm39.5mm
Power Reserve
Prospex Marinemaster Marinemaster 1968 Heritage Diver's Watch72h
Reef 39.5 mm56h
Water Resistance
Prospex Marinemaster Marinemaster 1968 Heritage Diver's Watch300m
Reef 39.5 mm300m
MSRP
Prospex Marinemaster Marinemaster 1968 Heritage Diver's Watch$3,600
Reef 39.5 mm$2,230

Full specifications

Case

4 specs
Diameter
42.6mm
39.5mm
Thickness
14.1mm
11mm
Lug-to-Lug
49.3mm
45.5mm
Lug Width
20mm
22mm

Crystal & Dial

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

Movement

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

Pricing

1 specs
MSRP
$3,600
$2,230

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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.

Seiko Prospex Marinemaster Marinemaster 1968 Heritage Diver's Watch

The Seiko Prospex Marinemaster 1968 Heritage Diver's Watch is widely praised for its excellent quality and finishing, with reviewers and owners noting its GS-level craftsmanship and Zaratsu-inspired polishing. Owners appreciate its refined design, comfortable case shape, and the 4:00 crown position, with some finding it more manageable on the wrist than other models. The Caliber 8L45 movement offers a 72-hour power reserve and accuracy within -5/+10 seconds per day, and the bracelet features an improved clasp with an extension system. However, some find the price point high, and one reviewer noted the unsigned winding crown as a missed opportunity. On balance, owners and reviewers rate the Seiko Prospex Marinemaster 1968 Heritage Diver's Watch highly for its premium finishing and tool-like appearance at its price point.

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.

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