The Blancpain Fifty Fathoms Automatique 5015-3630-52B is a 45 mm red gold dive watch with a black dial, a sapphire crystal bezel insert in place of the usual ceramic, and the in-house calibre 1315. It belongs to the modern Fifty Fathoms Automatique line, the core diving family Blancpain rebuilt around the historic 1953 Fifty Fathoms, and represents the precious-metal, dress-oriented end of that range. This guide covers the specifications, the sapphire bezel, how the red gold case compares with the steel version, price context and what to check before buying. Bizak & Co. sources the 5015-3630-52B to order; the Fifty Fathoms collection lists the configurations we can seek.
Last reviewed on September 28, 2026 by Filip Biczak. Prices are dated observations, not quotes.
Blancpain Fifty Fathoms 5015-3630-52B specifications
| Attribute | 5015-3630-52B |
|---|---|
| Case | 45 mm 18 ct red gold, unidirectional diving bezel |
| Bezel insert | Sapphire crystal, used on the precious-metal Fifty Fathoms Automatique references in place of ceramic |
| Movement | Calibre 1315, self-winding, silicon balance spring, five-day power reserve from three stacked barrels |
| Dial | Black with applied index hour markers and luminous coating, the standard Fifty Fathoms diving layout |
| Crystal | Sapphire, domed |
| Strap | Rubber, Blancpain's standard diving strap on the precious-metal Automatique references |
| Water resistance | 300 m, the modern Fifty Fathoms Automatique's rated depth |
Source: Fédération Horlogère Suisse, the Swiss watch industry federation, for background on Swiss manufacture standards that govern movements like the calibre 1315, and Phillips Watches for the Fifty Fathoms' standing as a collected diving reference at auction.
What is the Fifty Fathoms Automatique?
Blancpain introduced the original Fifty Fathoms in 1953 for French navy combat divers, generally credited as the first purpose-built modern dive watch alongside Rolex's early Submariner. The modern Automatique line, part of Blancpain's post-2003 rebuild of the Fifty Fathoms name, keeps the black dial, rotating bezel and oversized case proportions of the original while updating the movement to the in-house calibre 1315. The 45 mm case size used on the 5015 references is the larger of the two common Fifty Fathoms Automatique diameters, alongside a 42.3 mm size used on other steel and gold variants.
What does the sapphire crystal bezel do?
Most dive watch bezels, including the steel Fifty Fathoms Automatique, use a ceramic insert for its scratch resistance and colour stability. On the precious-metal 5015 references Blancpain instead cuts the 60-minute diving scale into a solid sapphire crystal insert, a harder and more technically demanding material to machine than ceramic. Sapphire resists scratching even more than ceramic, though it can chip under a sharp impact in a way ceramic generally does not. It is a detail aimed at buyers who want the diving function paired with a material more associated with Blancpain's dress and complication lines than with tool watches.
Red gold vs steel: which Fifty Fathoms Automatique 45 mm?
| 5015-3630-52B, red gold | 5015D-1140-52B, steel | |
|---|---|---|
| Case | 45 mm red gold | 45 mm steel |
| Bezel insert | Sapphire crystal | Ceramic |
| Dial | Black | Blue |
| Movement | Calibre 1315 | Calibre 1315 |
| Bizak catalogue ask, 27 Sep 2026 | US$41,399, brand new, sourced to order | US$16,599, brand new, sourced to order |
The two watches share the same case size and the same movement; the gap between them is the red gold case and the sapphire bezel rather than anything mechanical. A buyer who wants the Fifty Fathoms diving specification without the precious-metal premium gets essentially the same watch from the steel reference.
How does the 5015-3630-52B wear?
At 45 mm the Fifty Fathoms Automatique is a large watch by any measure, closer in scale to the largest steel professional dive watches than to a dress-diver hybrid. Red gold adds density on top of that size, so the case carries real weight on the wrist. The rubber strap is a deliberate counterbalance: it keeps the overall package sporting and comfortable despite the precious-metal case, and it is more practical near water than a metal bracelet would be on a gold case this size. Wrists comfortable with a large steel diver will carry the 45 mm case without difficulty; smaller wrists should try it on before ordering, since there is no smaller case option within this specific reference.
How much is a Blancpain Fifty Fathoms 5015-3630-52B? Price context in 2026
- Retail. Blancpain does not publish a single worldwide list price on a public page in the way some peers do; current pricing for precious-metal Fifty Fathoms references is set through Blancpain's boutique and authorised-dealer network and varies by market.
- Secondary market. Precious-metal Fifty Fathoms references with a sapphire bezel are a smaller slice of the line than the steel Automatique, so fewer examples circulate at any given time; box and papers matter more on a brand-new piece, since condition on an unworn watch should be effectively new.
- Bizak catalogue asks. On 27 September 2026 our sourced catalogue listed the 5015-3630-52B at US$41,399 brand new, against US$16,599 for the steel 45 mm blue-dial 5015D-1140-52B and US$41,299 for the red gold 45 mm blue-dial 5015-3603C-63B, all sourced to order.
Those figures describe what we saw and will move. Ask for a dated quote for the exact configuration; our Richard Mille price guide and Rolex Submariner price guide show how we present comparable pricing context for other precious-metal and dive references.
Is the 5015-3630-52B a good investment?
A red gold, sapphire-bezel Fifty Fathoms is a purchase for the specific combination of materials rather than a formula for appreciation. The steel Fifty Fathoms Automatique has a broader collector base and thicker secondary liquidity; the precious-metal, sapphire-bezel version is a narrower, slower-moving market by comparison. Buy it because you want the red gold case and the sapphire bezel specifically; if resale matters, ask for a written cash-buy assessment before you commit.
Buying a new 5015-3630-52B: what to check
- Full set. A brand-new watch should have all hang tags, the warranty card and the protective stickers intact, with an unactivated warranty start date.
- Sapphire bezel edges. Sapphire resists scratching well but can chip under a hard knock; examine the bezel edges and the engraved numerals under good light before accepting the watch.
- Case surfaces. Red gold shows handling marks differently than steel; on a genuinely new piece there should be no contact marks on the case flanks or lugs.
- Rubber strap. Inspect the full length of the strap and the buckle hardware for storage marks or creasing before the watch leaves the counter.
- Movement function. Confirm the winding rotor, date change and bezel click action all feel smooth and correctly aligned.
- Price against the band. A full-set example offered well under the steel version's price, or well under other red gold Fifty Fathoms Automatique references, is the single most reliable warning sign.
Our authentication process describes what we inspect before dispatch.
Quick answers
How much is a Blancpain Fifty Fathoms Automatique 5015-3630-52B?
Blancpain does not publish a fixed worldwide list price. Bizak's sourced catalogue listed the red gold 5015-3630-52B at US$41,399 brand new on 27 September 2026, against US$16,599 for the equivalent steel reference, both sourced to order.
What is the sapphire bezel on the Fifty Fathoms for?
It replaces the ceramic insert used on the steel Fifty Fathoms Automatique with a solid sapphire crystal 60-minute diving scale, more scratch-resistant than ceramic though more prone to chipping under a sharp impact.
What movement does the Fifty Fathoms Automatique 5015-3630-52B use?
Calibre 1315, Blancpain's in-house self-winding movement with a silicon balance spring and a five-day power reserve from three stacked barrels.
Is the Fifty Fathoms a real dive watch?
Yes. It is rated to 300 m water resistance and traces to Blancpain's 1953 original, generally credited alongside early Rolex Submariner references as one of the first purpose-built modern dive watches.
Is the Blancpain Fifty Fathoms 5015-3630-52B a good buy?
It suits a buyer who specifically wants the red gold case and sapphire bezel combination rather than the broader collector base of the steel version. We do not make investment claims; ask us to confirm current condition and set before you order.
Request a Fifty Fathoms 5015-3630-52B sourcing quote
Tell us the configuration and set you want, plus your budget and timing, through our sourcing enquiry form. We confirm the specific watch, photographs, papers and final price before you commit. Catalogue entries: 5015-3630-52B red gold black dial, 5015D-1140-52B steel blue dial; browse the Fifty Fathoms collection, the Blancpain collection, or sell or trade your Blancpain.
Related reading: Rolex Submariner price guide · Richard Mille price guide · Audemars Piguet price guide · Sell or trade a watch.
0 comments