On N. lake Michigan most marinas monitor 16/9 or 68. Cruising guides will usually tell you what channel each monitors, but in every case that I am aware of 16 is one of the channels. They quickly, and rightly, move you to another channel, but 16 is always active as a hailing channel. Champlain may be an exception because of poulation, as N. Lk Mi. is not active, but I have never heard of such a exception.
Sounds a little bit extreme to me.
What Tommy said. Brevity is the soul of wit, though. Here's a typical Ch. 16 exchange off Toronto:
"Alchemy, Alchemy, Alchemy, this is Tugboat, Tugboat, over.
Tugboat, Alchemy, go zero six.
Elapsed time, about seven seconds if my VHF is nearby. If ch. 6 is occupied, we return to ch. 16 and try again, usually on 27, 71 or 73.
Chs. 12 and 13 are used here for airport/ship and bridge-bridge communications here, but there's no special injunction against using 16 as a hail frequency other than keep it as concise as possible.