Dive deep into the Sicura HEXA 400 Green, featuring a distinctive hexagonal 316L stainless steel case and a serious 400-meter water resistance. Discover its vintage-inspired dual-crown compressor layout and modern dual-bezel system.
Today, we're taking a closer look at a diver that combines some serious vintage cues with modern build quality: the Sicura HEXA four hundred Green. This watch builds on Sicura's history from the nineteen sixties, bringing back a distinctive hexagonal case and a dual-crown compressor design.
First up is the Sicura HEXA four hundred Green. It comes in a forty-millimeter case made from three hundred sixteen L stainless steel, a standard for dive watches because it resists saltwater corrosion. The hexagonal shape is a nod to Sicura's vintage Diver four hundred models. This watch features a dual-bezel system: an internal rotating bezel controlled by the two o'clock crown and a conventional external unidirectional bezel with a black ceramic insert. Ceramic is a major upgrade here, resisting scratches and fading, which keeps the dive timing legible over years of use.
The watch measures forty-six millimeters lug-to-lug, making it a compact option for a robust diver. At twelve point five millimeters thick, it maintains a relatively slim profile for its water resistance rating. The dual crown setup at two and four o’clock controls the inner rotating bezel and the time setting respectively, keeping the case lines clean. The crystal is domed sapphire, which offers excellent scratch resistance and a vintage aesthetic that complements the case design.
Inside, it’s powered by a Swiss-made Sellita SW two hundred-one Élaboré-grade automatic movement. This movement is known for its reliability and easy serviceability, offering a thirty-eight-hour power reserve and running at twenty-eight thousand eight hundred vibrations per hour. A thirty-eight-hour power reserve means you can take it off Friday evening and it will need a rewind by Sunday morning, if you’re not wearing it. With four hundred meters of water resistance, it is a truly capable tool watch, suitable for serious diving or just peace of mind around water. The lume on the hands and markers uses Super-LumiNova for visibility in low-light conditions. The Sicura HEXA four hundred Green is priced at one thousand six hundred fifty-one dollars.
For more details on its specific hardware, including the unique dual-bezel system and how its forty-six-millimeter lug-to-lug wears on the wrist, head over to the Veloce Journal for the full breakdown.
The Sicura HEXA 400 Green anchors its design in a hexagonal 316L stainless steel case and a serious 400-meter water resistance rating. It combines a vintage-inspired dual-crown compressor layout with a modern dual-bezel system and a Swiss automatic movement. The price is set at $1,651.
40mmCase
$1,651Price
38hPower Reserve
400mWater Res.
This model, reference H400.SS.A.40ATM.04.SS, marks a significant moment for Sicura, a brand drawing on its dive watch heritage from the late 1960s. The design revives cues from historical models like the SuperWaterProof 400, bringing a distinctive case shape back to the market.
Sicura's return brings back a design language rooted in the tool watches of the late 1960s. The HEXA 400 is not a direct reissue but a modern interpretation of the brand’s historical Diver Compressor and SuperWaterProof 400 models. The most defining feature is the six-sided case, a direct link to the vintage Diver 400.
When we first looked at the revival of this line in our coverage of the Sicura Hexa 400, the focus was on its heritage. Here, we are diving deeper into the specific hardware of the Sea Green variant. While the history provides the foundation, the watch is built with entirely contemporary materials and specifications.
Case Architecture: The Hexagon and Twin Crowns
The case is machined from 316L stainless steel, a common choice for dive watches due to its high resistance to corrosion from saltwater. The profile is hexagonal, creating sharp facets that distinguish it from the typical round diver case. It’s a design that will be immediately recognizable to any dialhead familiar with vintage skin divers.
Sicura’s official specifications list the diameter at 40mm, with a thickness of 14mm and a lug-to-lug measurement of 46mm. These dimensions suggest a compact footprint on the wrist, with the 46mm length being particularly wearable for many. Note that while the technical sheet states 40mm, the product page also includes a "41 mm" icon, an inconsistency in the brand's own materials.
The watch uses a "compressor" style twin-crown system. The screw-down crown at 2 o'clock operates the internal rotating bezel, while the screw-down crown at 4 o'clock is used for winding the movement and setting the time and date. This setup is crucial for achieving the 400-meter (40 bar) water resistance rating.
The dual-bezel system is the HEXA 400's most functional feature. It combines the protection of an internal bezel with the utility of an external one, offering two independent ways to time events.
A Unique Dual-Bezel System
The HEXA 400 features two separate timing bezels. The first is the internal rotating bezel, controlled by the upper crown. Because it sits under the sapphire crystal, it is completely protected from accidental bumps and cannot be knocked out of position. This is a classic feature of vintage compressor divers.
The second is a conventional external unidirectional bezel with a black ceramic insert. Ceramic is used for its extreme hardness and resistance to scratches and fading from UV light, an upgrade over the aluminum inserts often used. This bezel provides the tactile, 120-click functionality that modern dive watch users expect.
Legibility and Lume
A dive watch's primary function is clear time-telling, especially in low light. The HEXA 400 addresses this with a matte green dial, which minimizes glare under bright sun or water. Applied indices and an oversized "12" provide strong orientation points.
The watch employs a dual-color Super-LumiNova application. The hands and hour markers glow blue, while the numerals and markings on the external bezel scale glow green. This color separation helps a user quickly distinguish between the time display and the elapsed time tracked on the bezel.
The entire dial is protected by a sapphire crystal. Sicura specifies that the crystal has multi-layer anti-reflective and anti-fingerprint coatings. The anti-reflective treatment is key for maintaining legibility by reducing the mirror-like effect that can obscure the dial outdoors.
Movement: The Sicura Engine Room
Inside the HEXA 400 is a Swiss-made Sellita SW200-1 in the Élaboré grade. The SW200-1 is a well-known automatic caliber, functionally equivalent to the ETA 2824-2, and has become a standard workhorse for many Swiss brands. It operates at a frequency of 28,800 vibrations per hour (4 Hz), which produces a smooth eight-beats-per-second sweep of the seconds hand.
The Élaboré grade signifies that the movement is adjusted in three positions and has better isochronism than the base "Standard" grade. The power reserve is a stated minimum of 38 hours. This is sufficient for daily wear but means the watch may stop if taken off Friday evening and not worn again until Monday morning.
Sicura’s marketing material mentions "Master Chronometer Certified" and regulation to ±4–6 seconds per day. It is important to note that "Master Chronometer" is a specific certification standard from METAS. The provided materials do not confirm independent METAS certification for this watch.
Bracelet and Clasp Details
The watch comes on a three-link bracelet made of brushed 316L stainless steel, matching the case material. The links are solid, and the brushed finish reinforces its identity as a tool watch. It avoids the flashiness of polished center links, keeping the focus on the angular case.
The folding clasp includes a safety lock to prevent accidental opening. More importantly, it features a tool-free micro-adjustment system. This allows the wearer to make small, precise changes to the bracelet length without needing tools, which is practical for accommodating wrist swell in warm weather or for fitting the watch over a wetsuit sleeve.
The Takeaway
The Sicura HEXA 400 Green is a tool diver positioned for enthusiasts who want robust, modern specifications in a case with clear vintage-inspired character. Its 400-meter rating, dual-bezel system, and Swiss automatic movement are its core technical arguments, while the hexagonal case provides a distinct identity in a crowded field of sub-$2,000 divers.
Frequently Asked Questions
What movement is in the Sicura HEXA 400?
The Sicura HEXA 400 uses a Swiss automatic Sellita SW200-1 movement in the Élaboré grade. This caliber features 26 jewels, a 38-hour power reserve, hacking seconds, and operates at a frequency of 28,800 vph (4 Hz).
Is the Sicura HEXA 400 a true dive watch?
Yes, its specifications meet and exceed the typical requirements for a professional dive watch. It features a 400-meter (40 bar) water resistance rating, twin screw-down crowns, a unidirectional rotating bezel, a sapphire crystal, and strong luminous markings for low-light visibility.
How does the dual-crown system work on the HEXA 400?
The watch has two screw-down crowns. The crown at the 2 o'clock position is used exclusively to rotate the internal timing bezel located under the crystal. The crown at the 4 o'clock position is for the movement functions: winding the mainspring, setting the date, and setting the time.
What is the history of the Sicura brand?
Sicura was a popular Swiss watch brand in the 1960s and 1970s, known for producing accessible and robust tool watches, especially divers. The new HEXA 400 revives the brand after a long absence, drawing direct inspiration from historical models like the Sicura Diver 400 with its hexagonal case.
What is the price of the Sicura HEXA 400 Green?
The official retail price for the Sicura HEXA 400 Green (Ref. H400.SS.A.40ATM.04.SS) is listed as $1,651 USD on the brand's official website.
Case
40mm × 14mm, 316L stainless steel
Movement
Sellita SW200-1 Élaboré, automatic, 38h power reserve
I originally started VELOCE to put my skills to work, hone my app design and web development practices, and dive deeper into the world of horology. I wanted to learn more about the watches, the brands, and the incredible people behind them - the creators, the designers, and the collectors. I love discovering new timepieces and sharing their stories with the world. VELOCE is my ultimate passion project and hobby, the creative space I head to after my full-time job to build something I truly care about.
By Nick·October 30, 2026· 6 min read
