Bremont Supermarine 300M Date Dive Watch
Starting from 4.000 €The Bremont Supermarine 300M Date is the British house’s contemporary diver, entirely redesigned around a slimmer, more wraparound case. Cut from 904L stainless steel, rare in this category, it measures 40 mm in diameter, with a black anodised aluminium unidirectional bezel and 300 metres of water resistance. Its black gradient dial, applied hour markers filled with Super-LumiNova and date window at 3 o’clock make it a legible, versatile dive watch equally at home underwater and in daily life. Offered in three versions depending on strap, steel, rubber or leather, it targets fans of tool watches assembled and tested in England.
Bremont Supermarine 300M Date dive watch
Bremont was born from the ambition of two brothers, Nick and Giles English, to revive a demanding strain of British mechanical watchmaking. The brand’s watches are assembled and tested in Henley-on-Thames, Oxfordshire, and that origin remains a strong marker of its identity. Over the years, Bremont has built a reputation on rugged timepieces, tested in real conditions, often developed in connection with military units and professionals of the air and sea.
The Supermarine is the maritime pillar of the house. Since Davide Cerrato took over as director in 2023, the range has been restructured around three clearly separated worlds: the air with the pilot’s watches, the land with the Terra Nova collection, and the sea with the Supermarine. Launched in 2024, the Supermarine 300M and its Date variant mark a deliberate break. The three-part Trip-Tick case, long emblematic of Bremont, gives way to a more classic, slimmer construction, while the new Wayfinder logo replaces the historic propeller.
These models succeed the earlier 40 mm Supermarine Type 300 and Type 301. The 300M Date is distinguished from the dateless version by its window at 3 o’clock, its round hour markers and its black gradient dial. It belongs to the permanent collection rather than a limited series, making it a versatile diver meant to last on the wrist.
Technical specifications Bremont Supermarine 300M Date
- Brand: Bremont
- Model: Supermarine 300M Date
- Reference: SM40-DT-SS-BK-B
- Indicative price: €4,000 to €4,300
- Movement: Automatic
- Power reserve: 50 h
- Calibre: Modified BE-92AV
- Diameter: 40 mm
- Thickness: 12 mm
- Water resistance: 300 m / 30 ATM
- Materials: 904L stainless steel
- Crystal: Domed sapphire
- Dial: Black gradient
- Strap: Steel, rubber or brown leather
- Warranty: Up to 5 years
The Bremont Supermarine 300M Date dive watch
The Supermarine 300M Date embodies Bremont’s maritime vision: a tool watch built for the water, yet measured enough to wear every day. Its 40 mm diameter case adopts a symmetrical silhouette fitted with crown and bezel guards, an architecture that prevents accidental adjustments and absorbs knocks without upsetting the watch’s visual balance. At 12 mm thick and 49 mm lug to lug, it stays compact for a 300 m water resistant diver and slips easily under a sleeve.
The choice of 904L stainless steel is uncommon in this category. This alloy, harder to machine, delivers a rich finish and excellent resistance to marine corrosion, which serves the model’s purpose directly. The unidirectional aluminium bezel, black anodised with a knurled edge, plays on metallic shine rather than the deep gloss of ceramic, with trapezoidal markers that extend onto the dial to form a navy-inspired reticle. Legibility is immediate thanks to the black gradient dial, the chapter ring bearing a printed minute scale, and the anti-reflective domed sapphire crystal. The case alone weighs just 75 g, a figure that explains the comfort felt as soon as it goes on the wrist, whichever strap is fitted.
Mechanics, legibility and choice of straps
Beneath the screw-down caseback sits the modified BE-92AV calibre, an 11 ½ line automatic movement with 25 jewels. It beats at 28,800 vibrations per hour, or 4 Hz, and delivers a 50-hour power reserve, enough to cover a weekend without winding. Bremont highlights components known for their stability, with a Glucydur balance wheel, an Anachron hairspring and a Nivaflex mainspring. The display keeps to essentials: hours, minutes, central seconds and date at 3 o’clock, a function that alone justifies the model’s name.
Night-time legibility relies on applied hour markers and polished nickel-plated hands filled with white Super-LumiNova® with blue emission, a key point both underwater and in low light. The caseback, engraved with a map of the world’s oceans, recalls this diver’s calling. Three versions coexist, differing only in strap and price. The most complete comes with a 904L steel bracelet of wave-shaped links alternating polished and satin finishes, with micro-adjustment at the clasp, priced at €4,300. The other two, at €4,000, offer a black chevron rubber strap with a military inspiration or a smarter brown stitched leather, both fitted with a pin buckle. The quick-release system is common to all three.
Bremont Supermarine 300M Date dive watch: British ruggedness
The Bremont Supermarine 300M Date combines a 40 mm 904L stainless steel case, a black anodised aluminium unidirectional bezel and a domed sapphire crystal with anti-reflective treatment. Its black gradient dial carries applied hour markers and nickel-plated hands filled with white Super-LumiNova with blue emission, alongside a date window at 3 o’clock. The modified automatic BE-92AV calibre beats at 28,800 vibrations per hour and offers fifty hours of power reserve. Water resistance reaches 300 metres thanks to a screw-down crown and a screw-down caseback engraved with a map of the oceans. Three quick-release straps are offered, in steel, rubber or leather.
Movement
The Supermarine 300M Date is powered by the modified BE-92AV calibre, an 11 ½ line automatic movement with twenty-five jewels. It oscillates at 28,800 vibrations per hour and delivers a 50-hour power reserve, enough to cover a two-day pause without resetting the time. Its construction relies on a Glucydur balance wheel, an Anachron hairspring and a Nivaflex mainspring, a trio chosen for timekeeping stability. The display includes hours, minutes, central seconds and the date at 3 o’clock.
Diameter and materials
The case measures 40 mm in diameter for 12 mm thick and 49 mm lug to lug, balanced proportions for a versatile diver. It is made of 904L stainless steel, a corrosion-resistant alloy uncommon in this price range. The black anodised aluminium unidirectional bezel has a knurled edge and trapezoidal markers that extend onto the black gradient dial. The domed sapphire crystal receives an anti-reflective and anti-scratch treatment. The 20 mm lug width makes strap changes easy.
Water resistance
With 300 m / 30 ATM water resistance, the Supermarine 300M Date comfortably covers recreational diving and all watersports use. This relies on a screw-down crown, protected by shoulders, and a screw-down steel caseback decorated with a map of the world’s oceans. The unidirectional dive bezel allows immersion time to be tracked without risk of overestimation, while the white Super-LumiNova® with blue emission on markers and hands ensures legibility in darkness.
Accessories
Three straps are available, all fitted with a quick-release system. The entirely new 904L steel bracelet lines up wave-shaped links alternating polished and satin finishes and includes clasp micro-adjustment to adjust fit throughout the day. The military-inspired black chevron rubber and the vintage brown stitched leather both use a pin buckle and a standard length suited to wrists from 16.5 to 22 cm. Bremont does not detail the contents of the box supplied with the watch.
Warranty
Bremont covers the Supermarine 300M Date with a 3-year international warranty. This period can be extended to 5 years for watches bearing the Wayfinder logo purchased after April 2024, provided the piece is registered through the My Club Bremont programme. Every watch is assembled and inspected in Henley-on-Thames, Oxfordshire, before shipping, a welcome guarantee of follow-up for a mechanical diver destined to be serviced regularly over years spent on the wrist, at sea as in daily life.
Bremont Supermarine 300M Date The pros
and cons
- 904L steel rare in this category
- 300 metres water resistance
- Compact 40 mm case
- 50-hour power reserve
- Warranty extendable to five years
- Calibre based on a Sellita base
- Aluminium bezel softer than ceramic
- No helium escape valve
- No ISO certification stated
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Prices and technical specifications are subject to change. Content and photos are not contractual.
