What channel should you monitor on a boat that utilizes the vhf frequency?

On a boat that utilizes VHF frequencies, you should monitor Channel 16 (156.800 MHz), which is the international distress, safety, and calling frequency. This channel is used for emergencies and hailing other vessels or the Coast Guard. Additionally, once a communication is established, you may switch to another channel for further discussion, but always return to Channel 16 for emergencies.