U-Boat Watch 1938 Doppio Tempo Green 8500. Its time to live your time, to enjoy every minute, decide how and where to spend it. Life is an adventure, taste every moment of it and collect all the emotions. U-BOAT unveils the new 1938 Doppio tempo range. Presented first time last year, based on a model originally created for the Italian army’s parachute assault regiment, the Col Moschin.