Tudor began producing their very own calibers in home (and, it must be said, independent from older sister manufacturer Rolex) from 2015, initially supplying them in their own North Flag game watch and in Pelagos diver’s watches. Since then, we have seen the steady introduction of fabrication calibers throughout Tudor’s lineup that appears to imply the position from the market Tudor Meaning is after. The new Tudor Black Bay Steel has exactly the Exact Same MT5612 as Tudor’s North Flag and Pelagos. So, though it is not a brand-new caliber, it’s still a pretty cool motion with 70 hours of power reserve, a marginally standard 28,800 bph operating speed, and a silicone hairspring at a price point where a completely in house movement is uncommon. The MT5612 is also new to the Black Bay range because previous models were non-date and used the only marginally different MT5602.Protecting all this from the components and water (this theoretically being a diver’s watch) is the same 41mm, 200m water resistant, stainless steel case, featuring alternating brushed and polished surfaces that Black Bay enthusiasts know too well. Also carried over from previous versions are the anti-reflective, domed sapphire crystal along with the Tudor rose engraved crown. Different here is the bezel insert which is made of steel rather than the aluminum present on preceding Black Bay versions. The steel insert looks tough and ought to add a measure of scratch resistance over aluminum while at the same time providing for a military-inspired rugged appearance.

Tudor has never made limited or unique editions, at least none that are publicly known. So the Heritage Black Bay One is a distinct departure from the norm. A one of a kind timepiece made for charity auction Only Watch, the Heritage Black Bay One is modelled on the regular production Black Bay, with a special dial and bezel inspired by the reference 7923 dive watch of 1954.

With the unique model reference 7923/001, the Heritage Black Bay One sticks to the formula Tudor has applied for all its Heritage timepieces. Not a literal remake of the original, the Black Bay One is heavily inspired by the 1954 model, but still different.

The bezel insert is black without minute markings, and a red triangle at 12 o’clock. And the dial is a wonderful pastiche of design elements from vintage Tudor and Rolex dive watches. It’s a glossy black gilt dial, with gold-tone markings and text. The hands are similarly gold-plated, as are the metal surrounds for the hour markers filled with luminous paint.

A particularly vintage touch, though not one found on the original, is the “200m=660ft” at six o’clock. This recalls vintage Rolex dive watches in its colour, while the text itself is reminiscent of the desirable “meters first” Rolex Submariners (that were later superseded by the more common “feet first” models).

Like the regular production Black Bay, the Only Watch edition has a 41mm steel case with a domed sapphire crystal and the ETA 2824 inside. Unlike the regular edition it’s fitted to a steel bracelet with retro-style straight ends that’s not offered with the regular Black Bay, though this bracelet is available on the Heritage Ranger. The Heritage Black Bay One will also be sold with an aged brown leather strap and a grey, jacquard-weave fabric NATO-style strap; multiple strap options packaged with the watch are standard for Tudor. Only Watch 2015, a biennial auction of one of a kind timepieces that raises money for research int Duchenne muscular dsytrophy, will take place in November 2015. Stayed tuned for more unique pieces that will be revealed in the coming months.