This is the Yellow Submarine — and if you know, you know. Officially the De Bethune DB28GS Yellow Submarine, Ref. DB28GSV2YN, this is the gilded, sun-warmed interpretation of De Bethune's first and only true dive watch, one of just 25 examples ever made. Collectors don't reach for the reference number when they talk about this watch; they simply call it the Yellow Submarine, with the kind of affection usually reserved for a watch you never intend to sell. De Bethune produces fewer than 400 timepieces a year across its entire catalogue, so a 25-piece run is not merely a limited edition — it is genuine grail territory, the sort of watch that rarely surfaces publicly and disappears just as quickly into a serious collection. Every visible surface is finished to an extraordinary standard, from the skeletonized bridgework to the beautifully integrated balance system and exposed gear train.

What makes the Yellow Submarine so beloved is that its golden glow is not gold at all. The 44mm case is grade-five titanium that has been heat-treated, or "fired," until its surface oxidizes into a warm, honeyed patina — the very same flame technique De Bethune made famous with its blued components, here coaxed toward yellow instead. The result is luxe and faintly aged, a tone no plating or alloy could ever replicate, and it carries right through to the openworked dial, where the fired-yellow titanium motion-works bridge, base-plate cap, and barrel bridge cap all glow with that same fire-born color and De Bethune's delicate Microlight engraving. The titanium case middle, bezel, lugs, and caseback are engraved with the brand's signature Microlight striations around the circumference, and the watch rides on De Bethune's patented floating lugs — an ultra-light yet durable construction that articulates to hug the wrist so comfortably the Yellow Submarine wears far more easily than its imposing proportions suggest. A sapphire crystal sits front and back, with the dive scale printed onto the front crystal so that it rotates together with the unidirectional 60-click bezel, while a screw-down crown keeps the watch water resistant to 105 meters — a depth chosen as a quiet homage to the freediving record that inspired the film Le Grand Bleu.

At the heart of this masterpiece beats the in-house De Bethune caliber DB.L.249, a highly refined manual-winding movement engineered with the brand's proprietary technologies and celebrated for both its technical performance and visual beauty. It runs at 28,800 vph with a silicon escape wheel and a titanium-and-white-gold balance for an ideal mass-to-inertia ratio, while twin self-regulating barrels deliver a full five-day power reserve, indicated on the dial near 9 o'clock. The whole assembly is protected by De Bethune's patented triple pare-chute shock-absorption system, a symmetrical balance bridge braced on both sides with shock absorbers at each end. THE YELLOW SUBMARINE'S SIGNATURE PARTY TRICK REMAINS ITS MECHANICAL LIGHTING: A PUSHER AT THE 6 O'CLOCK SPINS A MINIATURE DYNAMO OFF THE MAINSPRING BARRELS - EXACTLY LIKE A BICYCLE DYNAMO - TO POWER 4 LEDs THAT ILLUMINATE THE DIAL, WITH NO BATTERY AND NO ELECTRONICS ANYWHERE IN THE WATCH. Unlike the standard Grand Bleu and its proprietary "Blue Moon" luminescent compound, the Yellow Submarine uses a traditional white lume, a fitting rarity for a brand whose watches almost never carry lume at all.

This particular example is accompanied by its De Bethune Certificate of Origin and Warranty, presentation box, and both straps — the textured rubber strap and the additional canvas strap, secured by a titanium folding deployant clasp — and represents an exceptionally scarce opportunity for the serious collector seeking one of the most exclusive modern independent timepieces ever produced. With only 25 examples manufactured worldwide, the DB28GSV2YN "Yellow Submarine" rarely surfaces publicly and remains one of the most coveted creations from De Bethune's legendary DB28 collection: a true collector's piece blending haute horology, futuristic aesthetics, and mechanical innovation into a wearable work of art.