My VHF is on anytime I'm in the boat, including while anchored at a sandbar.
We monitor (scan) between ch 16 as well as another channel that we have designated as our "talk" channel. There has been numerous times that valuable information (typically weather related) has come across 16 -- even if it's a local boater reporting -- very simply and not tieing up the channel- a squall or rain report from a particular section of the lake. Other times it's been fog banks, etc.
On at least couple of occasions I have rendered assistance for a tow or "minor" aid -- as well as legitimate information being requested (not a radio check
).
Continuing off topic here -- I also noticed that this year Ch 16 seemed "quieter" to us -- without the horsing around on the channel as in years past -- the way it is supposed to be.