the Chase-Durer Special Forces Underwater Demolitions Team 1000 XL that is worn is a unique watch
but what's probably more in character is the Kobold Phantom because:
1. doesn't say Special Forces
2. automatic ETA 7750, not quartz (battery powered)
3. high quality design meant for tactical operations
4. it is extremely well made/expensive (like an Armani suit or Oliver Peoples Victory)
5. extremely durable because of three coats of PVD to keep it black as possible
6. and if he needed to trade the watch for transportation or a favor, it should get him about $5,250 best case.
http://www.koboldwatch.com/products/phantom.htm