Good point. There are no restrictions (at least in the US or high seas) on what you can listen to. And most ham operators have general coverage receivers. When I left for the Caribbean, I left my receiver tuned to Herb Hilgenbergs frequency (marine HF) and my wife could simply turn it on and wait for me to check in with him. That includes a position report so she could keep track. When it got difficult to receive me, a ham friend used his
rig to listen and relayed reports to her.
Anyone that sails on the East coast probably knows about Herb. For reference, look at:
http://www3.sympatico.ca/hehilgen/vax498.htm
Graham
AA2WR