I love the Big pilots used by the LH are awesome, but I personally favor the 50mm Breitling pocket watch used by US B-24 and 17 bombers and navigators. A little more artistic with a more complex 18 jewel movements.... up close they are a work f art... the detail is amazing... ( I can take better pics if anyone is interested). Also US military property which had to be checked in/ out for each mission.
The Brietling is pictured on the left, below. Worn on the wrist/ over the leathers with a rather Ingenious adaptor.
On the right is a 1909 -WWI era Zenith pocket watch... in a trench leather wrist band.