The IMO has issued guidance on the usage of AIS Safety Related Messages in distress situations. The use of safety related messages in these situations is not recommended.
"Certain models of class A Automatic Identification Systems (AIS) provided for preconfiguredsafety related messages, which have been used, without any procedural basis, to convey textmessages indicating distress situations. A similar situation is developing with respect to class Bequipment. Although most class B AIS are not required to provide short range messages, andmost do not, those that do must use preconfigured messages. AIS standards give no guidance asto what predefined messages should be used, in effect leaving it to manufacturers andAdministrations to decide.
IMO is of the view that the use of predefined distress text messages by AIS devices should be prohibited and not be considered a part of any distress and safety system at this time. While the GMDSS is foreseen to be subject to continuing improvements, and perhaps the use oftechnologies such as AIS may be considered in future, the current infrastructure, together with AIS technological limitations, do not support use of the text messaging facilities as part of the GMDSS.
Shore-based establishments may not be capable of receiving these text-type distress messagesand may not take the same responsive action as if an alert had been received over GMDSS equipment. Reliance on AIS text messaging in distress situations could result in untimely delays and increase the probability of fatalities.IMO intends to issue a circular to mariners describing the limitations of using AIS predefined distress text messages in distress situations."