iwc AQUATIMER CHRONOGRAPH Operating Instructions Manual page 8

Functions of the crown
X
Normal position
This watch has a screw-in crown. Screwing the crown
in to its normal position (X) prevents inadvertent adjust-
ment of the time or date and acts as a double seal
against ingress of water into the case. To release the
crown, unscrew it by turning it to the left, where it auto-
matically assumes position 0, the winding position.
By depressing the crown in position X and turning it to
the right at the same time, it is screwed down firmly
again and secured.
0 1 2
X Normal position
(screwed in)
0 Winding position
1 Date setting
2 Time setting