Hi Nobbles ,
ZE & TFoN are right - Tugela very nice spot , good fishing, though I wouldn't camp next to the river for safety reasons , unless u have quite a group. Rather stay in one of the self-help catering spots. Clean , safe etc. Not far to walk.
Mtunzini is huge fun , more safe than Tugela as said already , maybe more diversity wrt species. Take yr boat along for better exploration of the waters.
Amatikhulu has a camp site next to the river - fishing the mouth area is very on/off. Fishing the mouth /estuary does not produce size , but lots of fun on drop-shot/lures , especially higher up inland. Then the size increases if u start exploring the deeper holes / structures. Nice pick-handles/springer/rock-salmon/perch.
But that is up in the river , below the "old" prawn farm , and around and past the river bend, where the Nyoni river flows into the Amatikhulu. A kayak or small row boat with "sneaker" motors are allowed here.
Then you have Maphelane , camp very close to Umfolozi river , and nice Lobotes/perch and then odd shark showing its teeth in the river. Camp is short distance away.
The above is all suitable for light tackle fishing the mouth /estuaries & not talking about surf fishing.
Hope u come right.