What must a vessel do before conducting routine radio checks?

Before conducting routine radio checks, a vessel must check for ongoing communications on the frequency being used. This is important for several reasons. Firstly, it ensures that the vessel does not interfere with distress calls or other critical communications taking place on that frequency. Radio channels are often shared among multiple users, and broadcasting a radio check without checking for activity could disrupt important communications.

Additionally, being aware of ongoing communications helps the operator assess the traffic on the channel and choose an appropriate time to conduct the check, minimizing the risk of causing interference.

The other choices involve actions that, while potentially relevant in different contexts, are not a prerequisite for conducting routine radio checks. For example, notifying nearby vessels or obtaining permission from the Coast Guard is not necessary for a simple radio check, and performing a visual inspection of the equipment, though good practice, does not pertain directly to ensuring the radio check is done effectively without causing disruption.