iwc Portugieser Chronograph Mode D'emploi page 18

With the crown in the normal position (0), you can also wind the
automatic movement by hand. A few revolutions of the crown are
enough to start the movement. However, it is better to wind the
watch by turning the crown through approximately 20 revolutions
as this will ensure maximum accuracy. The crown must always be
in position 0 when you are wearing your watch.
F u n c t i O n s O F t h e c r O W n
0 —
1 —
n O r M a l p O s i t i O n
p O r t u g u e s e c h r O n O g r a p h
— 1 8 —
Normal position
Time setting
0 1