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Which Formex Reef is this?
The Reef name covers distinct watches and finishes. The specifications here concern Formex’s 42 mm stainless-steel Automatic COSC 300M models, including silver and blue variants. There is also a separate 39.5 mm forged-carbon version, while the Radiant Bronze is a distinct dial variant. Do not assume every Reef shares the steel model’s case, dimensions or dial finish. Formex lists the steel model on its silver product page and blue UK-currency product page; Fratello’s coverage is of the smaller forged-carbon model, not this 42 mm steel watch.
How big does the Formex Reef wear?
Formex specifies a 42 mm case diameter, 47 mm lug-to-lug, 11.4 mm height and 22 mm lug width. The manufacturer also calls its perceived height 9.4 mm; that is a separate maker-stated figure, not a replacement for the conventional 11.4 mm measurement. Formex lists the case-only weight as 90 g.
Those measurements provide a more useful fit check than diameter alone: compare the 47 mm lug-to-lug against the watches you already find comfortable, and account for the chosen bracelet or strap. No independent hands-on fit assessment of this exact steel model is established here, so wrist presence should not be inferred from coverage of the 39.5 mm forged-carbon Reef.
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#1 Best Overall
- Stainless steel case 40mm diameter x 14mm thick; Exhibition case back; Black dial; Luminous hands and hour markers
- NH35A Japanese Automatic movement, 24 jewel; Assembled in Malaysia; Watch weight: 155 grams
- Stainless steel band, 210mm L x 20mm W; Band is adjustable by adding/removing links; Fold over safety clasp
- Mineral crystal; Screw-down crown; Diver stainless steel bezel with black top bezel ring; 200 meter water resistant: Suitable for professional marine activity and surface water sports. Suitable for diving.
Movement and timekeeping
The stated movement is a Swiss-made, self-winding Sellita SW300-1 in chronometer grade, officially COSC-certified, with 25 jewels, a date display and a manufacturer-stated 56-hour power reserve. Formex’s blue product page says: “The REEF is powered by a Swiss Made Sellita SW300-1 self-winding movement with a power reserve of 56 hours.”
COSC certification describes the movement’s chronometer status; it is not a personal accuracy result for an individual watch. No measured rate test or long-term reliability evidence for this exact 42 mm model is established here.
Rank #2
- WATER-RESISTANT: these water-resistant men's dive watches are ISO scuba-approved to depths of 200 meters
- AUTOMATIC: these self-winding, automatic men's watches are powered by your movement, with a power reserve of 41 hours
- STAINLESS STEEL: features a durable 43.8mm stainless steel watch case and bracelet.
- LUMIBRITE DISPLAY: this men's automatic watch features a highly-legible display with LumiBrite hands and markers
- 4R35 CALIBER: equipped with the reliable caliber 4R35 automatic movement, this accurate men's watch keeps precise time
Case, dial and dive-watch features
Formex specifies a 316L stainless-steel case and a sapphire crystal with anti-reflection treatment. The water-resistance rating is 30 bar, 300 metres or 1,000 feet, according to the manufacturer. The blue product page describes double-gasket construction. A published rating is not a guarantee that a particular watch is suitable for a reader’s planned dive; follow the manufacturer’s guidance and ensure the watch is maintained appropriately.
Selected colorways use a unidirectional rotating zirconium-oxide ceramic bezel; Formex also lists a steel bezel option. The silver version is described as having a multi-finished, hand-applied dégradé dial, while the Radiant Bronze edition is separately described as vertically brushed bronze. BGW9 Super-LumiNova is specified on the hands and indices. These material and finish details vary by configuration, so confirm the exact dial and bezel before ordering.
Rank #3
- PREMIUM DESIGN:NH34 Automatic GMT diver's watch featuring a blue and red rotating bezel, black dial with luminous markers, and date display at 3 o'clock position
- MOVEMENT: Self-winding automatic mechanical movement with GMT function for tracking multiple time zones
- CONSTRUCTION: Stainless steel case and jubilee-style bracelet with secure folding clasp for durability and comfort
- WATER RESISTANCE: Professional diver's watch rated for underwater use with 200m water resistance capability
- VERSATILE STYLE: Classic dive watch aesthetic with red GMT hand and two-tone bezel makes it suitable for both professional use and daily wear
Strap, bracelet and clasp choices
Formex lists a black rubber strap or stainless-steel bracelet, with screwed bracelet links. The 22 mm lug width is the relevant measurement when considering strap compatibility. Quick-release hardware and micro-adjustment are part of the configurations described by Formex, but the included components can differ between choices.
The blue product page describes a carbon-fiber-composite folding clasp with up to 7 mm of fine adjustment. Treat that as a feature of the clasp configuration described there, not a promise that every Reef package includes that clasp. Check the selected watch’s listing for the exact strap or bracelet, clasp and adjustment hardware.
Rank #4
- Round watch featuring corrugated unidirectional bezel, luminous hands/markers, and magnified date window at 3 o'clock
- 40 mm, Length: 210mm, 23k gold-plated stainless steel case with mineral dial window. Movement Caliber: NH35A
- Japanese automatic movement with analog display
- Gold & Stainless steel tone bracelet with foldover clasp with safety closure
- Water resistant to 200 m (660 ft): In general, suitable for professional marine activity and serious surface water sports, but not scuba diving.
Price and availability depend on the exact listing
When accessed for this review, Formex’s silver 42 mm product page displayed CHF 1,760. Its blue UK-currency page displayed £1,820 and marked the blue variant sold out. These are page snapshots, not a universal price or confirmation of current stock; currency, configuration and availability can change. Check the relevant market listing directly before buying.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Is the Formex Reef 42 mm worth buying?
The specification makes the most sense for someone who wants a steel 42 mm watch with a 47 mm lug-to-lug, COSC-certified automatic movement, date, ceramic-bezel option and stated 300 m rating, and who is comfortable choosing between strap and bracelet hardware. Fit and configuration deserve as much attention as the headline movement or depth rating.
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- Steel and gold tone stainless steel case 40mm diameter x 14mm thick; Exhibition case back; Black dial; Luminous hands and hour markers
- NH35A Japanese Automatic movement, 24 jewel; Assembled in Malaysia; Watch weight: 152 grams
- Steel and gold tone stainless steel band, 205mm L x 20mm W; Band is adjustable by adding/removing links; Fold over safety clasp
- Mineral crystal; Screw-down crown; Unidirectional stainless steel bezel with black top bezel ring; 200 meter water resistant: Suitable for professional marine activity and surface water sports. Suitable for diving.
- Automatic movement means that this timeless watch powers a quality Japanese-automatic movement with the simple movement of your arm.
Before purchase, compare the case dimensions with a watch that fits you, verify the dial and bezel materials, and confirm the included bracelet or strap and clasp. If you are considering the 39.5 mm forged-carbon Reef, evaluate it as a different model rather than using its coverage as a proxy for the steel 42 mm watch.
