Citizen 901 Manual page 11

Minor exposure
to water (washing
face, rain, etc.) general washing work
NO
OK
OK
OK
Water-related use
Swimming and Skin diving,
marine sports
NO
NO
OK
OK
Scuba diving
using an air
tank
NO NO
NO NO
NO NO
OK NO
Operate the crown
or button when
the watch is wet
NO
NO
NO
NO
11