Formex Reef GMTvsSeiko Prospex Sea 1965 Heritage Diver's Watch
The numbers, the dial colors, the calibers — laid out so you can stop flipping between tabs.
At a glance
12 of 29 specs differFull specifications
Case
5 specsCrystal & Dial
3 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 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.
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.
The Seiko Prospex Sea 1965 Heritage Diver's Watch is praised for its refined engineering and updated features, including a 300m water resistance and a 72-hour power reserve from the Caliber 6R55 movement in a 40mm case. Owners note its better build quality and interesting finishing with a mix of polished and brushed surfaces. The "Tranquil Teal" variant features a jewel-toned dial with a rippling-water pattern. However, some owners consider the price too high, and concerns exist regarding the accuracy of the 6R movements, with some reporting theirs run slow. One review notes a reflective dial that impacts legibility. On balance, owners and reviewers appreciate the Seiko Prospex Sea 1965 Heritage Diver's Watch for its refined design and improved specifications over previous generations, despite some reservations about movement accuracy and price.
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