No speed limits, Ted. Get careless and you will get pulled over and checked, but if there's no evidence of impaired driving or recklessness there's no problem.
I wear a Lifeline vest, which is the best made for flotation and impact, and I have a kill switch cord attached to it. I've met some wardens, in their boats, at pretty high speed and have never been pulled over for it.
But, I am very judicious about when and where I let the horses run, so to speak.
Might I add, I am not a speed freak. On the highway I wear my seatbelt and set my cruise dead on the speed limits. But, I live 2 miles from the nearest boat landing and make good use of the proximity and the laws. No speed limit means exactly what it says, in Jawja.