huh. so CA boating law states an "operator means the person on board who is steering the vessel while underway" (same as operate) and "underway means all times except when the motorboat, sailboat, or vessel is anchored, moored or aground."
Seems prety clear and easy to understand to me.
If you are anchored, you are not underway, therefore when anchored there is no operator, therefore no issue...
right up until you cease being anchored, and the operator gets the boat underway.
In other words, just as in all things sailing related, commonsense and prudence apply.
Think of it like reefing. if you think you need to reef, you should. if you think you are in any way, even remotely, unable to operate your boat without blowing over, then stay anchored.
if you aren't able to make this decision prudently, or if you attract the attention of the watercops even while anchored, then you get what you deserve.
something tells me you are smarter than that.