To clear up confusion (maybe), the new law applies only when moving at planing/displacement speed.
It does not say “underway” (which is anytime you’re not anchored or moored, and not “making way”.)
Drifting is considered “underway”, even without a motor running. If your boat is moving and steering doesn’t change your course, you’re underway.
It also does not say “making way” (which basically means any speed that you’re able to steer to change course: ie 1-100+ mph)
“Planing/Displacement Speed” is a completely separate definition and description but does fall under “making way”. But “making way” doesn’t imply just planing alone.
Trolling is not “under way”, but “making way” and not “on plane or displacement speed”
Clear as mud??
Long story short, if your boat is going faster than 10mph, expect to be expected to wear your tether. We/You/I should be anyway.
I’m voluntarily getting better at it myself, but do forget sometimes.