Ralf Tech
WRB Automatic Black Ecume - Full-Set

“Some black watches try to disappear. Others use shadow to reveal what matters most: the light of the dial, the accuracy of a gesture and the quiet confidence expected from an instrument when conditions become difficult.”

RALF TECH WRB Automatic Black “Écume” reference WRB-1104, limited edition of 100 pieces, 39 mm black-PVD-coated, matte sandblasted 316L surgical-steel tonneau case approximately 13.5 mm thick, protected screw-down crown positioned at 4 o’clock, matte off-white dial inspired by sea foam, black-PVD-treated steel hands and Super-LumiNova Phantom hour markers, no-date three-hand display, 120-click unidirectional rotating bezel compliant with ISO 6425, black anodised aluminium insert with Super-LumiNova BGW9 triangular marker, 2.5 mm domed anti-reflective sapphire crystal, screw-down caseback engraved with the individual number, 22 mm lug width, 200-metre water resistance, RALF TECH calibre RTA003 automatic mechanical movement operating at 21,600 vibrations per hour, approximately 40-hour power reserve after full winding, 24 jewels, watch made in France, fitted with a black leather strap and accompanied by its original black silicone strap, delivered as a 2026 Full Set with Explorer case and documents, in near-mint pre-owned condition, fully inspected, authenticated and covered by a 3-year Mostra warranty.

The RALF TECH WRB Automatic Black Écume belongs to that second family. Its black case is not designed merely to create a dramatic all-black watch. It acts as a frame, absorbs unnecessary reflections and allows the pale dial to become the true centre of the piece. The contrast recalls white foam appearing upon a dark sea when wind raises the surface and turns water into moving reference points. The off-white sea-foam dial has a subtler presence than pure white. Its matte tone feels almost mineral, slightly warm under certain light and cooler when the watch moves into shadow. It immediately strengthens the legibility of the black hands and markers while giving this professional diver unusual elegance. The watch remains technical without ever resembling simple military equipment.

The matte sandblasted black PVD coating offers another practical advantage. It reduces reflections, creates visual continuity across the case and provides a more discreet surface than polished steel. The treatment improves surface resistance and discretion, without making the case indestructible against severe impacts. The 39 mm case explains much of the WRB’s success. It retains the spirit of the WRX and WRV in a more measured format, suitable for many wrists and comfortable throughout a long day. On this 2026 generation, the reduced thickness of approximately 13.5 mm further improves wearability: the watch remains solid but sits closer to the wrist, slips beneath a cuff and moves naturally from sporting surroundings to urban use. The crown at 4 o’clock also avoids the pressure sometimes felt on the back of the hand.  

The 120-click unidirectional bezel confirms that Black Écume remains a genuine dive watch. Its notching allows precise operation with wet or gloved fingers, while unidirectional rotation prevents accidental movement from suggesting that the diver has more time remaining underwater. The graduation stays clear and the luminous marker makes the starting point easy to recover as light fades. Its 200-metre water resistance, screw-down crown, closed back and thick sapphire crystal give the owner a much greater safety margin than a city watch. The WRB can accompany sea, pool, navigation, rainy hikes, travel and sudden changes of plan without permanent caution, naturally subject to valid pressure testing before immersion. RALF TECH states that its procedures go beyond theoretical depth and use tests varying duration, temperature, salinity and surroundings.   The Super-LumiNova Phantom display reinforces that identity. By day, the black hands and markers strongly structure the pale dial. In darkness, their luminous surfaces return and make the time easy to read without disturbing the overall design. The no-date display preserves symmetry and simplifies use: after several days at rest, the watch needs only to be reset and wound, without correcting a calendar.

The black leather strap gives this example a more urban character. It extends the PVD case, brings warmth to the wrist and lets the sea-foam dial become a luminous detail beneath a cuff. With a shirt, jacket, sweater or blouson, the WRB keeps its character without appearing out of place. It becomes a dive watch able to live in the city, not a dress watch disguised as a diver. The original black silicone strap immediately restores its professional purpose. Resistant to water, perspiration and heat and easy to clean, it stabilises the case during activity and makes full use of the 200-metre rating. The two straps provide a genuine benefit: leather accompanies everyday life and refined clothing; silicone suits water, sport, travel and more demanding use. The automatic RALF TECH RTA003 calibre favours reliability over complication. It operates at 21,600 vibrations per hour, rests on 24 jewels and offers approximately 40 hours of power reserve. It provides automatic winding, manual winding and hacking seconds for precise setting. Its proven architecture gives the owner a clear advantage: it remains understandable, robust and suited to long-term maintenance without turning the watch into an unnecessarily complex object.  

Black Écume also benefits from RALF TECH’s military and professional experience. The WRB was first launched in October 2019 in a version designed for French Army divers before becoming available to the public in February 2020. Founded by professional diver Frank Huyghe, the brand built its reputation around diving equipment, combat swimmers and specialist units; it states that it has now equipped its hundredth special-forces or elite unit across more than fifteen countries. The civilian WRB-1104 is not an individually issued watch, but its design directly benefits from that culture of feedback, legibility and resistance.  

For the customer, this background should not be understood as martial decoration. It appears in practical choices: a bezel that can be gripped quickly, a protected crown, highly contrasted reading, a thick sapphire crystal, genuine water resistance and a format compact enough to remain comfortable for hours. The same qualities serve a diver, military operator, navigator, technician, traveller or simply someone wanting a watch able to follow an active life without becoming a source of concern. From a collector’s perspective, the limited edition of 100 pieces has genuine coherence. The sea-foam dial, black PVD case, French production and connection with the WRB “Slim” generation give the reference an immediately recognisable identity. It is not rare simply because a number is engraved on the back; it is rare because its combination of colour, material and use cannot be confused with a conventional WRB.

The 2026 Full Set naturally strengthens this interest. The Explorer case, documents, original silicone strap and first-presentation elements preserve the watch within its context. Its near-mint condition retains the definition of the PVD finish, the precision of the bezel action and the freshness of the pale dial. The future owner therefore receives an immediately available piece still very close to its original state.

This example is offered as a 2026 RALF TECH WRB Automatic Black Écume WRB-1104 Full Set, fitted with a black leather strap and accompanied by its original black silicone strap, Explorer case and documents. The watch has been inspected with particular attention given to the movement, crown, bezel, PVD coating, dial, straps and water resistance. Choosing a RALF TECH WRB from Mostra brings a particular advantage with a watch intended for genuine use. Since 2025, the Mostra workshop in Aix-en-Provence has been officially recognised as a Certified RALF TECH Technical Centre for pre-owned watches, with procedures covering diagnosis, genuine parts, water resistance and final inspection. This Black Écume comes with a certificate of authenticity, priority support and a 3-year Mostra warranty.   A watch such as the WRB-1104 is chosen for the powerful contrast between its sea-foam dial and black case, for the functional discretion of PVD, for its versatile dimensions and its ability to withstand real use. It is also chosen for the reassurance of certified support, the freedom provided by two straps and that rare quality: entering a collection without ceasing to be the watch worn when conditions become less forgiving.