U-Boat Classico 45mm watch is the smaller version of the 53mm Classico CAS. It is available with a black dial which looks cool.
The watch case is constructed of three pieces of stainless steel. The top piece, which makes up the bezel, the middle case, and the case-back. As mentioned above, the reference 2268 measures in at 45mm and the reference 2272 measures a whopping 53mm. 
Between the 6:00 lugs the case is stamped “316L” indicating the quality of the steel. 316L is commonly used among top watch brands, except for Rolex, which uses an even higher quality steel known as 904L. I’m not sure why U-Boat felt the need to stamp the case so visibly? That touch I could do without, but it’s no bigee. On the 3:00 side of the case, just above the 5:00 lug, the individual production number is stamped. I actually think this is a nice touch and it adds some interest to an otherwise boring side of the case. The eye candy resides on the 9:00 side, which features two chronograph pushers, an over-sized canteen style crown protector, and a unique hinge that secures the canteen to the case when unscrewed – more details regarding this are below.
The dial of the U-Boat classico, at least this varation, is extremely legible. The black arabic numerals and other hour markers contrast nicely with the beigle colored dial. The numerals are raised, while the other hour markers are cutout from the top layer exposing a black bottom layer . This is very subtle and can only be seen upon close examination of the watch. These are really nice touches! Overall, I prefer the look of the 53mm model – the dial is less cluttered and the sub-dial positioned at 12:00 doesn’t cut into the number 12 on the dial. 
The case-back is a sight to behold. Not only is it outfitted with a sapphire crystal. The entire case has a brushed finish and the overall shape of the case and lugs are very nice.
The movement is a 25 jewel Valjoux / ETA 7750 chronograph that’s been modified to display the date at the 9:00 position and to relocate the crown position from 3:00 to 9:00. The rotor has been engraved with the U-Boat logo – a nice touch. Other than that, it’s a basic looking ETA movement with no obvious decorations. The movement ticks at 28,800 BPH, so you have a smooth sweeping chrono and seconds hand. 
This watch has a 44 hour power reserve, so it’ll only need to be manually wound if you don’t wear it for a couple of days. This particular watch is running just outside of COSC specs at +7 seconds per day. Although that’s not spectacular timekeeping, I’m okay with that result.
