IWC Schaffhausen Aquatimer Split Minute Chronograph Mode D'emploi page 22

Functions of the crown
X
Normal position
This watch has a screw-in crown. The screw-in connection (normal position,
position X) prevents unintentional adjustment of the time or the date, and the
watch case has double protection against penetrating water. To release the
secure crown, unscrew it by rotating it to the left, where it automatically as-
sumes position 0, the winding position. By depressing the crown in position
X and rotating it to the right at the same time, it is screwed down firmly again
and secured.
Winding position
In the winding position (position 0), you can also wind the automatic move-
ment by hand. The movement will start after only a few revolutions of the
crown. However, it is better to wind the movement fully with about 30 revolu-
tions of the crown, as maximum accuracy and a power reserve of about
44 hours will then be assured, even after taking off the watch.
0 1 2
X Normal position (screwed in)
0 Winding position
1 Date setting
2 Time setting