San MartinSN0021
Homage to the Tudor Black Bay 36
about$326
Regular price at the brand's own website, checked 31 Oct 2026. Marketplace prices change often.
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The San Martin SN0021 is a homage to the Tudor Black Bay 36, with a 37 mm case, 1 mm larger. It uses an automatic movement and is water resistant to 100 m. It costs about $326 at the official store.
Side by side with the original
Compared with reference M79500. Values marked ≈ are estimates, such as a reviewer's measurement.
| Spec | SN0021 | Black Bay 36 (M79500) | Difference |
|---|---|---|---|
| Case diameter | 37 mm | 36 mm | +1 mm |
| Lug-to-lug | 45.5 mm | Not published | Can't compare |
| Thickness | 11.3 mm | ≈ 10.5 mm | +0.8 mm |
| Lug width | ≈ 20 mm | ≈ 19.5 mm | +0.5 mm |
| Water resistance | 100 m | 150 m | |
| Movement | Automatic, PT5000 or ST2130 | Automatic, ETA 2824 (modified by Tudor) | |
| Power reserve | Not published | 38 h | |
| Crystal | Sapphire, aR coating | Sapphire | |
| Bezel | Fixed, smooth | Fixed, smooth polished steel | |
| Case material | 316L stainless steel | Stainless steel | |
| Lume | BGW-9 on hands and markers | White luminous material on indices and hands | |
| Bracelet | 316L solid stainless steel brushed bracelet, 20 mm tapering to 16 mm | Steel Oyster-style, brushed centre links with polished sides, tapering 19 to 16 mm | |
| Weight | 125 g | Not published |
- ≈ SN0021, Lug width: median of 3 agreeing independent measurements (20 mm); the maker does not publish it.
- ≈ Black Bay 36, Thickness: median of 2 agreeing independent measurements (10.4–10.5 mm); the maker does not publish it.
- ≈ Black Bay 36, Lug width: median of 2 agreeing independent measurements (19–20 mm); the maker does not publish it.
The original
Tudor
Black Bay 36
Reference M79500, steel oyster-style bracelet
- Case
- 36 mm
- Lug-to-lug
- Not published
- Thickness
- ≈ 10.5 mm
- Water resistance
- 150 m
- Movement
- Automatic, ETA 2824 (modified by Tudor)
- List price
- Not published
Why it scores as it does
Proportions and movement are computed from specs. Design details and functions are judged from the brand's official images. How we score
Lug-to-lug is neither published nor measured for one of the two watches, so there is not enough data to score.
Proportions— / 30
- Case diameter8 / 121 mm apart
- Lug-to-lug0 / 8Not published, left out
- Thickness4.4 / 60.8 mm apart
- Lug width3 / 40.5 mm apart
Design signatures— / 40
- Angular snowflake hour and minute hands5 / 10Angular snowflake hour hand with a lume fill and a capped seconds hand in the official images. The minute hand is a slim tapering lume stick, not a second snowflake-style hand.
- Large applied luminous hour markers, triangle at 12 and rectangles at 3, 6 and 99 / 9Large applied lume markers: triangle at 12, rectangles at 3, 6 and 9, and round markers elsewhere, as in the official images.
- Smooth fixed polished steel bezel with no timing scale7 / 7Smooth fixed polished bezel with no scale in the official images.
- Glossy dial with raised indices3 / 6The B3 listing has enamel dials with a gloss finish and raised markers; the B2 listing is matte, as the brand describes it.
- Oyster-style bracelet with brushed centre links and curved end pieces4 / 4Three-link brushed bracelet with polished sides and end links that follow the case in the official images; the brand lists a brushed solid-link bracelet.
- Diamond-shaped lume plot near the seconds hand tip4 / 4Small diamond-shaped lume plot on the seconds hand near the tip in the official images of both listings.
Functions and materials— / 20
- Complications8 / 8Time only, no date window, as on the original.
- Bezel action4 / 4Fixed bezel, as on the original.
- Case and bezel materials4 / 4316L stainless steel case, bezel and bracelet, as on the original's steel.
- Crystal shape and date window4 / 4Sapphire with no date window or cyclops, as on the original; the brand lists a top-hat shape.
Movement type— / 10
- Movement type10 / 10Same movement type.
What reviewers and owners say
Reviewers
From 7 reviews we read or watched, 1 of them with a watch supplied by the brand.
Reviewers liked the compact 37 mm case, the polished and brushed finishing, the domed sapphire crystal, the evenly applied BGW-9 lume and the solid-link bracelet with a milled clasp. They found the case slim and comfortable on small and medium wrists. Several said the finishing compares well with much dearer watches, and two said the lume is better than on the same case with classic hands.
The complaints were the ghost date position on a dateless watch (the PT5000 has a date function the dial does not use), a short bracelet that may not suit wrists above about 7.5 inches, and a clasp that two reviewers of the B2 listing found had only two micro-adjust holes where the listing says four. One reviewer found the bracelet screws loose on arrival. One reviewer who compared it side by side with the original found a flatter, less deep black dial, off-white rather than crisp white markers, a domed crystal in place of a flat one, and a less refined clasp and crown. They also report that the lug width is 20 mm on the B2 and 19 mm on the B3.
Good
- Compact 37 mm case with a short lug-to-lug
- Domed top-hat sapphire crystal with AR coating
- Even, long-lasting BGW-9 lume
- Solid-link bracelet with a milled clasp
- Polished and brushed case finishing
- Dateless dial with a clean layout
Less good
- Ghost date position on a dateless watch (three reviewers)
- Clasp had two micro-adjust holes in B2 units; the listing says four (two reviewers)
- Bracelet is short for wrists above about 7.5 inches
- Lug width differs between listings: 20 mm on B2, 19 mm on B3
- Sharp case edges and a clasp that needs some force to close (one reviewer)
Versions and colours
- B2 matte black dialFollows the Black Bay 36 M79500 (steel oyster-style bracelet)about $326
- B2 matte blue dialIts own colourway, not on the originalabout $326
- B3 matte black dial with gilt printIts own colourway, not on the originalabout $326
- B3 enamel green dialIts own colourway, not on the originalabout $326
- B3 enamel light blue dialIts own colourway, not on the originalabout $326
- B3 enamel dark blue dialIts own colourway, not on the originalabout $326
Compare
Sources
Checked 31 Oct 2026. Every figure on this page comes from one of these pages.