DELMA Shell Star Big Date

DELMA revisits a significant part of its history with the introduction of the new Shell Star Big Date. This contemporary dive watch draws direct inspiration from the company's inaugural professional diver, the original Shell Star launched nearly half a century ago. The new release seeks to merge the robust, function-first design principles of its ancestor with modern horological advancements and materials, presented in two distinct gradient dial variations designed for legibility and aesthetic appeal.



The story of the Shell Star collection is intrinsically linked to DELMA's evolution as a watch manufacturer, particularly in the demanding field of underwater timekeeping. Back in 1975, the launch of the first Shell Star marked a pivotal moment for the brand. It wasn't just another watch; it was DELMA's confident entry into the specialized world of professional dive instruments. This timepiece established a standard for durability and underwater reliability that would guide the development of subsequent Delma dive watch families for decades to come.



The original 1975 Shell Star was conceived during an era when mechanical dive watches were essential tools for underwater exploration and work, not merely accessories. Its design prioritized water resistance, visibility in low-light conditions, and the ability to withstand the pressures encountered deep beneath the surface. The success and reputation of this pioneering model solidified DELMA's credentials and encouraged a continued focus on creating timepieces capable of performing in extreme aquatic environments, setting a benchmark for the brand's future endeavors in this category.



Carrying this legacy forward, the latest additions to the Shell Star line incorporate a prominent "Big Date" complication. Positioned clearly at the 12 o'clock mark, this feature utilizes two separate discs to display the date in large, easily readable numerals. This is a departure from traditional date windows and adds a distinct visual characteristic to the dial, enhancing functionality without compromising the layout. The Big Date serves as a practical improvement, making the date instantly legible at a glance.



The design approach for the Shell Star Big Date carefully balances respect for its heritage with the demands of contemporary watch enthusiasts and divers. It retains the purposeful, tool-watch character associated with the Shell Star name while integrating modern manufacturing techniques and aesthetic touches. The focus remains squarely on creating a tough, reliable instrument built for challenging conditions, whether submerged hundreds of meters or navigating daily life on land. This philosophy is evident in the choice of materials, the construction methods, and the functional features incorporated into the watch.



One of the two available versions features a captivating blue gradient dial (reference 41703.736.6.041). The color transitions smoothly across the dial surface, perhaps darkening towards the edges, creating a sense of depth reminiscent of the ocean's changing hues. Contrasting sharply against this blue backdrop are bold, applied hour markers rendered in a vibrant orange lume. This high-contrast combination, along with similarly treated hands, is crucial for underwater visibility. The Big Date display at 12 o'clock is framed in the same eye-catching orange, tying the design elements together and drawing attention to this key complication. A black unidirectional bezel surrounds the dial, providing a functional frame.



The second variant (reference 41703.736.6.091) offers a different but equally striking visual experience with its rich brown gradient dial. This version exudes a warmer, earthier tone, with the gradient effect providing visual interest and depth. Like its blue counterpart, it employs the same bold, applied orange luminous indexes and hands, ensuring excellent legibility against the darker dial background. The orange-framed Big Date complication remains prominently positioned at 12 o'clock, offering a consistent functional and aesthetic anchor across both models. The black dive bezel provides the same functional contrast as seen on the blue version.



At the heart of the watch's robust construction is its substantial case, milled from 316L stainless steel. This particular grade of steel is widely used in watchmaking for its excellent corrosion resistance and durability. The case measures a significant 44mm in diameter, giving it a strong presence on the wrist, while the height is a manageable 13.8mm. The distance from lug tip to lug tip is 51mm, and the lug width accommodates a 24mm strap or bracelet, contributing to the watch's bold stance.



The case finishing employs a combination of techniques to create visual interest and underscore its tool-watch nature. Broad surfaces typically feature a satin-brushed finish, which helps to minimize the appearance of minor scratches and reduces glare. Contrasting this are polished beveled edges along the case flanks and potentially around the bezel or lugs. This interplay between brushed and polished surfaces adds a touch of refinement without detracting from the watch's overall robust character.



Essential for any serious dive watch is a reliable sealing system, and the Shell Star Big Date incorporates key features to achieve its impressive depth rating. A screw-down crown is utilized, meaning the crown threads securely into the case. This mechanism creates a tight seal, preventing water ingress, which is critical for maintaining water resistance, especially at significant depths. The crown itself is made of stainless steel and likely features grooves or knurling for easy grip, even with wet hands or gloves.



A feature indicative of the watch's professional diving aspirations is the inclusion of a helium escape valve (HEV). This small, often automatically operated valve is typically located on the side of the watch case. Its purpose is specifically related to saturation diving, where divers live in pressurized environments containing helium for extended periods. During decompression, tiny helium molecules that may have penetrated the watch case need to escape faster than they entered to prevent pressure buildup that could potentially damage the watch or dislodge the crystal. The HEV allows this trapped helium to vent safely.



The combination of the robust case construction, screw-down crown, and secure case back allows the Shell Star Big Date to achieve a substantial water resistance rating of 500 meters, equivalent to 50 atmospheres or approximately 1650 feet. This level of water resistance far exceeds the requirements for recreational scuba diving and places the watch firmly in the category of professional-grade dive instruments, capable of handling deep-sea exploration and demanding underwater work.



Surrounding the crystal is a crucial tool for divers: the unidirectional rotating bezel. Made with a black anodized aluminum insert, this bezel features markings typically indicating elapsed minutes, usually with more detailed markings for the first 15 or 20 minutes and numerals at 10-minute intervals (e.g., 10, 20, 30, 40, 50). The bezel rotates in only one direction (counter-clockwise) as a safety measure. This ensures that if the bezel is accidentally knocked, it can only show that more dive time has elapsed, not less, preventing a diver from overstaying their planned bottom time.



Protecting the gradient dial is a sapphire crystal. Sapphire is synthetically produced and is prized in watchmaking for its exceptional hardness, second only to diamond. This makes it highly resistant to scratching, ensuring the dial remains clearly visible even after rough use. To further enhance legibility, the crystal is treated with an anti-reflective (AR) coating. This coating minimizes reflections and glare, making it easier to read the time, especially in bright sunlight or underwater where light conditions can vary.



Looking closer at the dial, the applied indexes stand out prominently. Instead of being merely printed, these markers are physically attached to the dial surface, adding a sense of dimension. They are generously filled with Super-LumiNova C3, a high-performance phosphorescent material. This material absorbs light energy and then glows brightly in the dark, providing essential low-light visibility for reading the time deep underwater or during nighttime hours. A detailed minute track likely runs along the periphery of the dial, allowing for precise time-setting and reading.



The hands – hour, minute, and central seconds – are designed for instant recognition. Typically, dive watches feature broad, distinctively shaped hands to maximize surface area for lume application and ensure they stand out against the dial. The Shell Star Big Date follows this principle, with the hour, minute, and seconds hands all treated with Super-LumiNova C3, matching the indexes and guaranteeing readability in all lighting conditions. The central seconds hand often features a distinct marker or color near its tip for added visibility.



The Big Date display at 12 o'clock deserves special mention as a defining feature. Unlike standard date windows showing a single numeral, the Big Date uses two adjacent discs, viewed through a double aperture, to display the date in large, clear digits. The bright orange frame surrounding this aperture on the Shell Star Big Date not only highlights the complication but also integrates it visually with the orange accents found on the indexes and potentially the hands, creating a cohesive and striking dial design.



Powering the Shell Star Big Date is a Swiss automatic movement combination: the well-regarded ETA 2892-A2 serves as the base caliber, augmented by a Jaquet 3512 Big Date module. The ETA 2892-A2 is known for its reliability, relatively slim profile, and efficiency. It operates as a self-winding movement, meaning it harnesses the motion of the wearer's wrist to wind the mainspring via a rotor, eliminating the need for manual winding if worn regularly.



This specific movement configuration provides the central display of hours, minutes, and sweeping seconds, along with the prominent Big Date function. It operates at a frequency of 28,800 vibrations per hour (4 Hz), a standard for many modern Swiss movements, contributing to good timekeeping stability. The movement contains 21 jewels, which are synthetic rubies used at critical friction points to reduce wear and enhance longevity. When fully wound, it offers a power reserve of approximately 42 hours.



Adding an element appreciated by watch enthusiasts, the Shell Star Big Date features a transparent case back. Secured by four screws, this screw-down stainless steel back incorporates a window made of mineral crystal. While not as scratch-resistant as the sapphire on the front, mineral crystal provides adequate durability for this component and allows a view of the decorated ETA 2892-A2 movement beating within. Observing the automatic rotor spin and the balance wheel oscillate offers a glimpse into the mechanical heart of the watch.



Completing the package is a robust stainless steel bracelet designed to match the watch's rugged character. It employs a classic three-link construction, a style known for its durability and comfort. The outer links feature a brushed finish, consistent with the primary case finishing, while the narrower center links are polished, providing a subtle contrast that echoes the polished accents on the case. This combination gives the bracelet a versatile look suitable for both active pursuits and daily wear.



The bracelet secures to the wrist using a stainless steel deployant clasp, often referred to as a safety clasp. This type of clasp folds over itself and locks securely, typically requiring activation via side pushers to release. This design provides extra security against accidental opening, an important consideration for a watch intended for active use, especially underwater. The 24mm width where the bracelet meets the case ensures a balanced and substantial feel that complements the 44mm case diameter. Weighing in at 150 grams, the watch has a noticeable but manageable presence on the wrist.



The DELMA Shell Star Big Date is positioned as a versatile timepiece, engineered for the rigors of professional diving yet suitable for everyday challenges and adventures on land. Its specifications, including the 500m water resistance, helium escape valve, robust construction, and highly legible display, confirm its capability as a serious dive instrument. Simultaneously, its refined finishing, gradient dials, and the practicality of the Big Date function make it wearable in a wide range of settings.



Adding to its appeal is its exclusivity. DELMA has announced that the Shell Star Big Date will be produced as a limited edition, with only 100 pieces being made available worldwide. This limited production run enhances the desirability for collectors and enthusiasts seeking a watch that combines historical significance, modern features, and rarity. Each piece represents a small fraction of DELMA's ongoing dive watch legacy.



The new DELMA Shell Star Big Date models are set with a retail price of CHF 2250 in Swiss Francs, USD 2750 in US Dollars, and EUR 2500 in Euros. Launched in April 2025, these limited-edition timepieces represent a continuation of the Shell Star heritage, offering a blend of professional dive watch capabilities, a distinctive Big Date complication, and the exclusivity of a 100-piece run for discerning watch buyers and diving professionals.



Case: 316L stainless steel, 44mm diameter, 13.8mm height, 51mm lug-to-lug, 24mm lug width. Brushed and polished finish (satin-brushed surfaces, polished bevels). Sapphire crystal with AR coating, screw-down crown, helium escape valve. Screw-down case back with 4 screws and mineral crystal exhibition window. Water resistant to 50 ATM / 500 m / 1650 ft. Black anodized aluminum unidirectional diver bezel. Weight 150g.

Movement: ETA 2892-A2 with Jaquet 3512 Big Date module. Self-winding automatic. Functions: Hours, minutes, central seconds, Big Date. Power reserve of 42 hours. Frequency: 28,800 A/h. Contains 21 jewels.

Dial: Gradient blue or gradient brown options. Applied indexes with Super-LumiNova C3. Hour, minute, and central seconds hands with Super-LumiNova C3. Large, orange-framed Big Date display at 12 o'clock. Minute track present.

Strap: Stainless steel three-link bracelet. Brushed outer links and polished inner links. Stainless steel deployant safety clasp with pushers.

Price: CHF 2250 / USD 2750 / EUR 2500

Reference Number: 41703.736.6.041 (Blue Gradient), 41703.736.6.091 (Brown Gradient)

Notes: Limited edition of 100 pieces total. Features professional dive specifications including 500m water resistance and a helium escape valve. Prominent Big Date complication at 12 o'clock. Modern iteration of the original 1975 DELMA Shell Star.