iwc 3717 Mode D'emploi page 26

Reading the time in the dark
The dial and the hour and minute hands of your watch
are provided with luminous elements that permit the time
to be read easily, even in total darkness. The distinctive
triangle at 12.00 acts as a reference point.
Water-resistance
The indicated quantity in metres does not correspond to
the dive depth, but rather to the test pressure to which the
watch was subjected in the course of a standard testing
procedure. The water-resistance of your watch can be
adversely affected by the sudden and repeated differen-
ces in water pressure that can arise during swimming,
for example, and by sudden changes in the water tem-
perature.
In order to ensure its perfect function, you must have your
watch inspected by an IWC service point at least once a
year. An inspection must also be carried out after the
watch has suffered abnormal stresses (shock). If these
inspections are not carried out as stipulated, or if the
watch is opened by unauthorized persons, IWC will
decline any guarantee or liability claims.
Recommendation: Your authorized IWC Official Agent
must perform a new water-resistance test every time your
IWC watch is opened and serviced.