In the United States, MARAD (Marine Administration) sends out infrequent advisories about potential global political climate dangers.
These meteorological advisories include the development of weather systems such as and not limited to, rain squalls, big tidal drops, major current shifts, lightning storms, hurricane and tsunami warnings, high winds, and cyclones.
This includes, but is not limited to injuries on deck, imminent collision that has not yet occurred, or being unsure of vessel's position.
Mayday: This is the most important call that can be made, due to the fact that it directly concerns a threat to life or the vessel.
GMDSS protocol requires that the safety call must be spoken to attract attention of the selected vessels.