The Umgeni is rather challenging. I'm not good at the rates, but it's definitely way above grade 3
There were rocks like steep steps with big loose chunks, so that it was hard to get a grip. In fact, we managed to bottom out our 4x4 once on that track. 
Not really re-assuring when you look to your left or right and see the scarp right next to you...We only found out on the last day that the other two are much more accessible and enjoyable. But we'll be back and will get on the others.
and with some driving skills doable without proper 4x4.
