“It’s not a sin to get knocked down, it’s a sin to stay down.” These are the words of Mr Carl Brashear – a man who got knocked down more than most. For anyone who might not recognise the name, or who never saw Men Of Honor, the 2000 biopic starring Mr Cuba Gooding Jr, he was one of the first Black Americans to qualify as a US Navy Diver – facing intense discrimination and prejudice as he did so.

In 1966, a mid-air collision between a US B52 bomber and its refuelling tanker plane (part of a Cold War defence initiative to have a fleet of nuclear bombers orbiting the planet on a constant basis) resulted in four hydrogen bombs falling to earth around the Spanish town of Palomares. It became known as the Palomares Incident and makes for a fairly shocking story in its own right. Three of the four bombs landed near the town and exploded without detonating the nuclear elements of the warheads, dispersing radioactive plutonium over the local area. To this day, the clear-up operation is incomplete, with the last round of talks in 2015 between the US and Spain resulting in only a statement of intent to reach a binding agreement to clean up the area and dispose of the contaminated soil.

But we digress: the fourth bomb fell into the Mediterranean, precipitating a massive search and salvage operation, and that’s where Brashear comes in. He was serving on board the USS Hoist at the time (one of 23 ships involved in a four-month search) and was one of 150 divers enlisted to find the missing bomb. When an on-deck accident saw his left leg crushed by a falling pipe, he was airlifted to Germany and on to the US, before the injured leg was eventually amputated below the knee.

Not to be held back, Brashear recovered and re-trained: two years later he became the first amputee to be certified as a US Navy Diver, and two years after that became the first Black American to achieve the rank of Master Diver. He served for a further nine years, retiring to a government desk job in 1979. After his death in 2006, his sons, DaWayne and Phillip, established the Carl Brashear Foundation, which has worked with Swiss watchmaker Oris since 2012.

Oris – which has a long history of working with maritime charities of various kinds (usually environmental, but not exclusively) – has always reserved the Carl Brashear association for its bronze-cased limited edition watches, as a direct nod to the diving equipment used in Brashear’s era. This year, it has released perhaps the most significant – certainly the most horologically accomplished – watch to bear the legendary diver’s name: the Oris Carl Brashear Caliber 401 Limited Edition.

To look at, it seems relatively straightforward: a 40mm bronze-cased dive watch with a dark blue dial and vintage-tone luminous hour markers. But it’s what’s inside that’s different, as the name might imply. Calibre 401 is the latest upgrade to Oris’ in-house Calibre 400 movement, a recent step into a whole new segment for the brand as it looks to compete with other “manufacture” makers. The 401 removes the date window and adds the small seconds dial at six o’clock, but otherwise retains the key features that make it an impressive movement for the money: a five-day power reserve, anti-magnetic resistance and a 10-year warranty. And of course, every time you wear it, you’ll know you’re paying tribute to a true pioneer.