Yup, true enough. If you're in the Brisbane area, ausfisher Subzero does a 1 day course every month or so. It's a good day and even though I've had an aviation radio licence for years, I still found that I learnt quite a bit. If you're elsewhere, contact your local VMR base, they should be able to tell you where to do a course.
I think technically you can have one on the boat as long as you don't have it switched on - available for emergencies then - but I wouldn't like to have argue the point if someone booked me. I reckon its worth doing anyway.