Which of the following is NOT a function of Channel 13?

Channel 13 is designated for specific communication functions in the maritime environment. It primarily serves as a bridge-to-bridge communication channel, allowing vessels to communicate with each other regarding navigational matters, especially in congested areas such as near bridges and locks. This channel plays an important role in ensuring safe navigation by facilitating the exchange of information that helps maintain safe distances and coordinate movement between vessels.

The use of Channel 13 for emergency distress calls is not its designated function, which is why this answer is correct. Distress calls typically occur on Channel 16, which is specifically reserved for emergency communications, allowing for immediate responses from nearby vessels and emergency services. Therefore, while Channel 13 supports important communication for navigational purposes and bridge operations, it is not utilized for emergency distress calls, which are critical and need to be prioritized on the appropriate channel.