Overview
The 39mm Sinn 8820T comes in three different dial variants. Plain sterile dial, yellow U-Boat dial and red U-Boat dial. Unconfirmed information says that the U-boat dials were limited to 200 watches each and only for the Asian markets and the sterile dials were distributed globally.
The 8820T is special, because it is Sinn’s first full titanium watch and features a capillary depth gauge. The watch is also interesting, because it doesn’t have direct Heuer cousin reference like many other Sinn 80s dive watches.
My interest in the Sinn 8820T came after realising that Sinn 8820T has nearly everything the brands new lineup has. In a way 8820T is very similar to T2, but the watch also resembles Sinn’s other dive watches such as the U1/U50.
| Manufacturer | Sinn |
| Reference | 8820T |
| Movement | ETA 2892-A2 |
| Diameter | 39mm |
| Thickness | 12mm |
| Lug to lug | 45mm |
| Lug width | 20mm |
| Material | Titanium |
| Water Resistance | 200 m |
8820T, 801A, 805 and 809 aut
Despite being Sinn’s first titanium watch, the 8820T is only one of many Sinn’s 80s dive watches along with 801A, 805 and 809 aut. The 801A shares a case with Heuer 980.023 Deep Dive / Spirotechnique watches and comes with impressive 100ATM depth rating.
On the other hand, the 805 is built into a classic Monnin case and the 809 shares genes with Heuer 980.004. While the 801, 805 and 809 were both offered with automatic and quartz movements, it appears that 8820T was only available with an automatic movement. Without confirmation from Sinn, it is only possible to speculate the years the watches were produced.
| Reference | Case Manufacturer | Similar | Start of Production |
|---|---|---|---|
| Sinn 801 | Heuer 980.023, Auricoste Spirotechnique | Late 1980s | |
| Sinn 805 | MRP SA | Heuer 980.006 | Early 1980s |
| Sinn 809 | MRP SA | Heuer 980.004 | Late 1980s / Early 1990s |
| Sinn 8820T | MRP SA | Squale 1535 Squale 1553 (Among others) | Mid 1980s |
The Case
The case of the 8820T is 39mm side-to-side, 43mm from lug-to-lug and 11mm thick. The size alone makes the watch invisible on the wrist. Combined with its titanium construction, the watch is both light and slim and wears extremely well on a nato strap. Like the 805 and 801, the 8820T is built into an outsourced case produced by MRP SA.
The Bezel
The bezel is machined into the case to protect it from accidental adjustment. To turn the bezel, user has to grip the bezel from sides and twist. The bezel has a painted tritium triangle at twelve o’clock position that can wear off. The numbers on the bezel are painted as well, making them subject to wear over time. The bezel action is sufficiently toolish and resembles Heuer references of the same era.
The Bracelet
The bracelet of the Sinn 8820T is made by the legendary Novavit SA (NSA). The bracelet itself is made out of folded titanium and resembles modern Sinn H-link bracelets, but rattles wiggles like a true vintage bracelet. The special feature of the bracelet is the patented NSA spring-loaded divers extension on the clasp. The NSA bracelets with this clasp offer instant micro-adjustment by spring-loaded pulling and recessing automatically. Unfortunately, this mechanism is subject to failure over time due to fatigue of the spring.
The NSA bracelet is a rare part and could be made out of unobtanium and thus it is very difficulty to source one. However, the bracelet is shared by Sinn 8827 and Sinn 8826. The end-links for these watches are different as the 8820 takes in less curving end-link, whereas the Sinn 8826 and Sinn 8827 have more curvature in the end-link. If you have the correct end-links, but a short bracelet, you can try to look for extension links (or message me because I have some and an extra clasp) or cannibalise a watch for its bracelet.
Serviceability
I queried about the service of the bracelet and the watch directly from Sinn. It looks like Sinn doesn’t have the crystals in stock anymore and water resistance cannot be guaranteed. Likewise, Sinn doesn’t have bracelets or their extension links for the NSA style bracelets. Communication from Sinn was good and exact, and they explained carefully what they will do to the watch. The final price of the service was aligned with the quote.
The service price list on Sinn site is reasonable. However, you will need to factor in shipping the watch. When serviced by Sinn, the service price is in the ballpark of 200-400 euros. The final price for my Sinn 8820T was 350€ including shipping costs. This included new crown, clasp spring and movement service. The service took over four months, but it is hard to make judgement here as I had a Sinn 156 sent there simultaneously.
Conclusion
Sinn 8820T can be considered a grandparent of Sinn T2 and perhaps even Sinn U50. The watch has a very distinctive look with its NSA bracelet. The watch is light and only 11mm thick making it virtually unnoticeable when worn. Due to the thinness, the watch wears well worn on a NATO although you may have problems fitting some of the thicker NATO straps due to the lug and spring-bar positioning.
The tritium compound on the dial and hands seem to age evenly, and makes a very pretty patina over time. This can be seen in many examples photographed online. The only downside is that the lug to lug of the watch is short, so it wears relatively small to those who have the big watch kink.
Ghost of Gerald Genta 
One response to “Sinn 8820T”
Hello fellow Sinner,
I’m a great admirer of Sinn timepieces and I own several, 15 in fact as its the brand that resonates with me the most. I came across your informative post as I just recently purchased a Sinn Uboat, one of my Sinn grails. Condition is a bit ruff but functioning. Sadly, the bracelet is missing one end link to connect it to the case. I would gladly purchase this piece or trade for it.
Dr.Sinn
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