Distress Signals.
When a vessel is in distress and requires assistance she shall use or exhibit the signals described in Annex IV to these Regulations.
The above rule is self-explanatory. Only those signals listed in Annex IV to these Rules may be used as distress signals. An amendment is pending with regard to Distress Signals, that will remove reference to Rt and WT Distress Signals such as the Radio telephone alarm etc. However, until this amendment comes into force, Annex IV must still be learnt in its present format.