Inter-ship and Working Channels

If the other vessel's MMSI is known, MCA guidance gives an Individual DSC routine call that indicates the proposed inter-ship channel. After acknowledgement, the conversation starts on that channel. If the MMSI is unknown, make the brief low-power voice call on Channel 16 and move once contact is established.

A channel shown as inter-ship on one current channel plan may be restricted, unavailable or assigned differently in another jurisdiction. Check current local information and the radio's channel plan; do not assume that every numbered channel works identically everywhere.

Keep the working exchange purposeful. Identify both stations, pass the necessary information, use low power first for nearby routine traffic and end cleanly so both vessels can restore their required watch.