Hazard 4 HWD BlackTie GMT Edition Dive Watch
Starting from 840 €The Hazard 4 Heavy Water Diver BlackTie Yellow GMT Edition is a tactical dive watch that owns its oversized build. With a titanium case measuring 50 mm and water resistant to 300 metres, it belongs to the family of instruments designed for extreme environments, far removed from the classic 40 mm diver. Its central argument lies in the illumination: self-powered Swiss gaseous tritium micro-lamps that glow continuously, with no recharging and no dedicated battery. The GMT function adds a day/night ring and a second time zone hand, useful to travellers and operators alike. Offered in three catalogue versions, it combines military legibility, raised stencil numerals and a Swiss quartz movement, for a resolutely utilitarian positioning.
Hazard 4 Heavy Water Diver BlackTie Yellow GMT Edition dive watch
Hazard 4 is the tactical line from Civilian Lab, a California company best known for its bags, chest rigs and modular carry systems aimed at the military, field photographers and EDC enthusiasts. Watchmaking occupies a singular place within the brand: it offers only one model, the Heavy Water Diver, split into two families, one with three hands and the other fitted with a second time zone. Design work is done in-house in Simi Valley, California, while the movement comes from Switzerland.
This approach explains the watch’s character. Rather than follow the established codes of the diver, Hazard 4 transposed its equipment-maker logic: an oversized case, a heavily knurled bezel to stay manageable with gloves, stencil-cut numerals on two levels and a 24-hour scale built into the dial. The declared aesthetic draws on submarine portholes, with a marker set inside the 12 o’clock opening.
The real point of difference remains the tritium illumination. The micro-lamps used here rely on the same technology as the night sights on handguns: hydrogen-3 gas sealed inside glass tubes, paired with phosphors. They do not charge from light, do not fade over the course of the night, and draw no energy from the movement at all. The brand deliberately sets them proud of the dial surface, so they stay visible from an angle and not only face-on. The GMT variant, introduced in 2017, extended this platform to tracking a second time zone, without giving up anything of the watch’s underwater vocation.
Technical specifications Hazard 4 Heavy Water Diver BlackTie Yellow GMT Edition
- Brand: Hazard 4
- Model: Heavy Water Diver GMT Edition
- Reference: Depending on version
- Indicative price: ≈ €840
- Movement: Quartz, Swiss movement
- Calibre: Ronda 515
- Diameter: 50 mm
- Thickness: 15 mm
- Water resistance: 300 m / 990 ft
- Materials: Bead-blasted grade 2 titanium, natural finish or black PVD
- Crystal: Scratch-resistant anti-reflective sapphire
- Dial: Black, sand
- Strap: TPU sport strap
- Warranty: Up to 2 years
- Box contents: Watch, thermoformed case
The Hazard 4 Heavy Water Diver BlackTie Yellow GMT dive watch
The Heavy Water Diver BlackTie Yellow GMT is not after discretion. Its 50 mm case in bead-blasted grade 2 titanium takes over the whole wrist, with a 15 mm thickness that gives away its underwater ambitions. Choosing titanium keeps the mass down to around 108 grams, a reasonable weight for such a size, while offering a hypoallergenic and resistant material. The matte bead-blasted finish limits reflections and suits the brand’s tactical spirit. The black dial is built on two levels: the numerals are cut in 3D stencil form, topped by an angled minute chapter ring that improves readability from an angle.
A 24-hour scale is built into the dial, complemented on this variant by the day/night ring specific to the GMT version. The date window sits at 4 o’clock, a placement that preserves the symmetry of the main numerals. Yellow accents animate the whole, on the bezel as well as on certain markers, while the broad hands remain instantly identifiable. The sapphire crystal receives an anti-reflective treatment on its inner face, to preserve contrast in full sun as well as underwater. The rotating bezel is heavily knurled, designed to be operated with thick gloves or wet hands. The crown, large and textured, turns easily despite its screw-down system. The whole forms a legible, robust instrument, designed first for use rather than for display.
Swiss tritium and three catalogue versions
This model’s signature lies in its illumination. Hazard 4 fits the dial and hands with Swiss-made gaseous tritium micro-lamps, self-powered and permanent. Unlike luminescent paint, they need no prior exposure to light and do not fade gradually through the night. Their 12-year half-life simply means their intensity halves over that period. A distinctive feature: the tubes are not recessed but protrude 80% above the dial surface, which makes them visible from an angle. An additional tritium marker sits in the 12 o’clock window of the 60-click unidirectional bezel.
Within the GMT collection, three versions coexist. The BlackTie Yellow described here pairs a natural titanium case with a black dial featuring yellow accents, fitted as standard with a TPU sport strap. The BlackTie White uses the same natural titanium case with a white GMT set, but comes fitted with a titanium bracelet, at the same price. The Cavern, the most expensive of the three, adopts a black PVD titanium case and an earth-tone GMT finish, also delivered on a metal bracelet. The titanium bracelet remains available as an option on the yellow version, the swap carried out using removable screwed pins.
Hazard 4 Heavy Water Diver BlackTie Yellow GMT Edition dive watch: tactical and legible
Designed in California and powered by a Swiss Ronda 515 quartz movement, the Heavy Water Diver BlackTie Yellow GMT measures 50 mm in diameter by 15 mm thick. Its bead-blasted grade 2 titanium case, water resistant to 300 metres, has a screw-down crown and caseback along with an anti-reflective sapphire crystal. The black dial with 3D stencil numerals incorporates a 24-hour scale, a date at 4 o’clock and protruding tritium micro-lamps. The 60-click unidirectional bezel carries a tritium marker at 12 o’clock. Delivered on a 24 mm TPU sport strap with a thermoformed case, it comes in three GMT versions.
Movement
The watch is powered by a Swiss-made Ronda 515 quartz calibre, fed by a mercury-free 371 silver oxide battery. The autonomy claimed by the brand is around two years from fitting, a duration that can vary depending on exposure to heat or cold. The GMT variant adds a second time zone hand along with a day/night ring allowing the daytime hours to be distinguished from the nighttime hours of the tracked zone. A choice consistent with the model’s utilitarian vocation.
Diameter and materials
The 50 mm case is machined from bead-blasted grade 2 titanium, with a thickness of 15 mm and a weight of around 108 grams. The finish comes in natural titanium on the BlackTie Yellow and BlackTie White versions, and in black PVD on the Cavern. The scratch-resistant sapphire crystal receives an internal anti-reflective treatment. The 60-click unidirectional bezel carries markers machined from solid metal and a tritium marker at 12 o’clock. The black dial displays 3D stencil numerals on two levels.
Water resistance
The 300 m / 990 ft water resistance places this Heavy Water Diver in the category of genuine divers, well beyond the needs of recreational diving. This resistance rests on a screw-down caseback and a screw-down crown, the latter deliberately large and textured to remain easy to operate. The 60-click unidirectional bezel allows the timing of a dive, with a tritium marker set in the 12 o’clock window. The tritium micro-lamps ensure permanent visibility at depth.
Accessories
The BlackTie Yellow GMT is delivered fitted on a 24 mm TPU sport strap, accompanied by a military-grade thermoformed carry case and a warranty authentication card. The BlackTie White and Cavern versions, for their part, arrive fitted with a titanium bracelet, offered as an option on the yellow version. The strap is swapped using screwed pins, removable by the user with a Torx 6 bit not supplied. Hazard 4 offers an online battery replacement and resealing service.
Warranty
Hazard 4 covers this Heavy Water Diver with a one-year warranty, extended to two years if the buyer registers their product within 30 days with the brand. Coverage extends to the movement, case, crystal, strap and tritium tubes. It is however reserved for purchases made through an authorised retailer, which excludes grey market channels and the secondhand market. A quick registration process therefore doubles the coverage period at no extra cost.
Hazard 4 HWD GMT The pros
and cons
- Permanent tritium illumination, no recharging
- 300 metre water resistance
- Lightweight grade 2 titanium case
- Swiss Ronda 515 quartz movement
- Second time zone and day/night ring
- Very imposing 50 mm diameter
- 15 mm thickness
- Titanium bracelet sold separately
- Tritium brightness fades over time
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Prices and technical specifications are subject to change. Content and photos are not contractual.
