Houthi attacks in the Red Sea give rise to curious attempts by cargo crews to thwart them. For several days, captains have been trying to send messages to Yemeni rebels via the international AIS system.
AIS is an automatic intensification system intended to make maritime navigation safer, by avoiding collisions at sea. Some crews transiting the Bab el Mandeb Strait add written messages in order to protect themselves from an attack. The UN authorizes the shutdown of AIS under certain conditions, particularly in areas affected by maritime piracy.