If a diver suspects that his buddy or a nearby diver may be in distress, he or she can send a remote SOS signal to the diver.
If the diver does not require assistance, he can choose to disable the signal.
In case he does not disable it and in fact is in distress, his unit will activate an automatic SOS signal.
The SOS signal is received by all other divers (within 1,000m or 1,100 yards) using the UDI system, allowing them to navigate to the diver in distress following the graphical instructions on their clear view screens.