Formex Reef 39.5 mmvsSeiko Prospex Marinemaster Marinemaster 1965 Heritage Diver's Watch
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At a glance
12 of 29 specs differFull specifications
Case
4 specsCrystal & Dial
4 specsMovement
3 specsPricing
1 specsFollow this matchup
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Owners + reviewers, side by side
Synthesized for each watch independently from owner discussions, enthusiast forums, written reviews, and video reviewers.
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.
The Seiko Prospex Marinemaster 1965 Heritage Diver's Watch is praised for its faithful re-creation of the 62MAS design, with reviewers noting improved wearability due to smaller case sizes (38mm to 40mm) and updated bracelets. Specific models feature a stainless steel case with super-hard coating, ceramic bezel, and a tool-free extension system on the bracelet. Accuracy figures vary, with one model rated at -5/+10 seconds per day and another at -10/+15 seconds per day, powered by movements like the Caliber 8L45 or 6L37 offering 72-hour or 46-hour power reserves respectively. Some reviewers point out drawbacks such as an unsigned winding crown, a lack of tool-free micro-adjust on the clasp for certain models, and a secondary GMT function on one variant. The price point, ranging from $2,800 to $3,600, is considered high by some, especially when compared to other Seiko or Grand Seiko offerings.
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