ThornT012
Homage to the Seiko Tuna
about$219
Regular price at the brand's own website, checked 1 Nov 2026. Marketplace prices change often.
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The Thorn T012 Titanium Shroud GMT Diver is a homage to the Seiko Tuna, with a 47 mm case, 2.4 mm smaller. It uses an automatic movement and is water resistant to 200 m. It costs about $219 at the official store.
Side by side with the original
Compared with reference SBBN047. Values marked ≈ are estimates, such as a reviewer's measurement.
| Spec | T012 | Tuna (SBBN047) | Difference |
|---|---|---|---|
| Case diameter | 47 mm | 49.4 mm | −2.4 mm |
| Lug-to-lug | Not published | 49.4 mm | Can't compare |
| Thickness | 14.8 mm | 16.3 mm | −1.5 mm |
| Lug width | Not published | Not published | Can't compare |
| Water resistance | 200 m | 1000 m | |
| Movement | Automatic, NH34 | Quartz, 7C46 | |
| Power reserve | Not published | Not published | |
| Crystal | Sapphire | Sapphire | |
| Bezel | 120-click unidirectional rotating bezel, Dual-colour aluminium insert with a BGW9 lume dot at 12 | Unidirectional rotating bezel | |
| Case material | Grade 2 titanium | One-piece (monobloc) case with black super-hard coating | |
| Lume | Swiss C3 super-luminous and vintage lume; BGW9 on the bezel dot | LumiBrite on hands, indexes and bezel | |
| Bracelet | Genuine leather strap, 22 mm | Black silicone strap | |
| Weight | ≈ 81 g | 118.5 g |
The original
Seiko
Tuna
Reference SBBN047, prospex marinemaster professional 1000 m, black dial, black silicone strap
- Case
- 49.4 mm
- Lug-to-lug
- 49.4 mm
- Thickness
- 16.3 mm
- Water resistance
- 1000 m
- Movement
- Quartz, 7C46
- 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 diameter2.4 / 122.4 mm apart
- Lug-to-lug0 / 8Not published, left out
- Thickness3 / 61.5 mm apart
- Lug width0 / 4Not published, left out
Design signatures— / 40
- Shroud around the case10 / 10A titanium shroud with visible screw heads surrounds the case, as in the official close-up.
- Round lug-less monobloc case5 / 10Round shrouded case with the lugs tucked under it, but a screwed-on shroud with a separate caseback rather than a one-piece case.
- Cut-outs in the shroud giving access to the bezel2 / 4The shroud is cut away around the knurled bezel so it can be gripped, but the cut-outs are shaped differently.
- Brushed hands in the 1975 style0 / 6Bevelled sword hands with lume plates and a yellow skeleton GMT hand, not the original's 1975-style hands.
- Matte black dial with large white indices6 / 6Matte black dial with large bevelled white-lume indices.
- Unidirectional dive bezel2 / 4The brand lists a 120-click unidirectional bezel, but its insert has a compass scale with a day and night split rather than dive minutes.
Functions and materials— / 20
- Complications4 / 8Date at 3 plus a GMT hand on a 24-hour scale; the original shows day and date. The brand does not say whether the GMT hand moves independently.
- Bezel action4 / 4120-click unidirectional bezel per the brand; the original's bezel is unidirectional.
- Case and bezel materials2 / 4Grade 2 titanium shroud and case; the original is a coated one-piece steel case.
- Crystal shape and date window4 / 4Sapphire crystal, as on the original.
Movement type— / 10
- Movement type0 / 10Different movement type.
What reviewers and owners say
Reviewers
From 2 reviews we read or watched.
Both reviewers liked the titanium shroud case and its finishing, and the dial detailing: bevelled markers and a yellow skeleton GMT hand. One praised the compass-scale bezel insert with its flush lume pip. Both found the bezel action gritty or imprecise, one noting some side play and that titanium bezels rarely feel as crisp as steel. Both rated the leather strap highly: supple out of the box, with flared ends that meet the shroud. The lume was called clean and long-lasting, though one said it would not outshine a Seiko diver. Both said the watch wears smaller than its 47 mm diameter suggests, with a lug-to-lug length of about 44 to 46.5 mm, and one measured 14.2 mm thick. One reviewer wished for more anti-reflective coating because of glare.
Good
- Light titanium case with a finished shroud
- Compass-scale bezel with a flush lume pip
- Supple leather strap with flared ends (both reviewers)
- Bright BGW9 lume
- Wears smaller than 47 mm suggests (both reviewers)
Less good
- Bezel action is gritty with some side play (both reviewers)
- Little or no AR coating, with glare in sunlight (one reviewer)
- 47 mm diameter and 14.2 to 14.8 mm thick
- Brand lists no lug-to-lug length
Known quality issues
Each reported by at least two independent sources.
- The bezel action is gritty or imprecise, with some side play on one unit and a titanium-on-titanium feel, reported by both reviewers.
Compare
Sources
Checked 1 Nov 2026. Every figure on this page comes from one of these pages.