How long must a ship maintain silence after sending a QRT SOS signal?

A ship is required to maintain silence after sending a QRT SOS signal for the duration of the communication. This means that the vessel must refrain from broadcasting any other messages unless absolutely necessary. This practice is in place to ensure that the channel remains clear for emergency communications.

Maintaining silence helps ensure that distress messages are not interfered with and that responses from other ships or shore stations can be heard clearly. The silence should continue until the distress situation has been addressed or resolved, permitting other vessels to respond effectively without confusion.

The other options, while they may contain elements of effective communication practices, do not convey the requirement for maintaining silence relative to the specific context of emergency signals like the SOS message. Hence, they do not align with the best practices established for maritime distress signaling.