Are there advantages in using raft/float for fly fishing for Yellowfish and other species in  the Orange river? 
As with trout fishing, fly fishing for yellowfish, without a doubt have many advantages in a raft in a river the size of the Orange River. The inflatable rafts are able to cover distances effortlessly, and position fishermen at the top of remote and prime fishing pools or rapids that are highly advantageous. In fact, most productive fishing areas exist that are not accessible in any other way besides on the water. The mountainous terrains hugging the river in most areas are even inaccessible to choppers.
Fly fishing with rafts in The Orange River in South Africa is not that much different from the New Zealand or North American counterparts. In North America, occupants of a raft or drift boat will be casting to likely water while drifting in the raft. In New Zealand Rivers, they have been successful in approaching feeding trout with a raft in only a few circumstances. For the most part, we all use the raft as a vehicle to access distant and remote pools, where we can affect our approach on foot. In most cases, trout will be spooked by an approaching raft long before they are within casting range. The same applies in South Arica especially the lower Orange or Orange River for that matter. If the raft floats over a rapid it spooks mostly largemouth yellowfish. Catfish will be actually attracted to the raft.Smallmouth yellowfish are not that skittish however and they can be caught right next to the rafts.

Rafting/floating is almost the  perfect method of fishing for the not so physical or mobile or aged fly fishermen.
Rafting and fishing is particularly advantageous for anglers who are unable to walk very far or walk at all but it also cuts on downtime for even extremely fit fly fishermen. Accessing distant fishing over a slippery rocky riverbed is strenuous stuff, and not everyone is up to it. This is where the raft comes into its own. By using the raft, we can put an angler on more fish, with less effort on his/her part and cover large sections of the rivers if need to. It also creates a very different feel to the fishing experience.
 What is further a great advantage is that the fly fisherman’s partner that doesn’t fish can travel with between fishing zones and have a base to operate from while enjoying themself. I.e. one can transport a chair, cool boxes, towels etc for the ladies and they thus form part of the fishing experience. While hubby walks the rapids they can take photos, tan, read a book do bird watching, take short walks etc. Always using the raft as the base.
Inflatable rafts make it easier to sneak up to quiet areas where largemouth yellowfish hold and can thus be approached without noise. We use the rafts mostly to get to the areas of fishing that can normally not be fished due to the size of the river and the distances. In long quiet pools the small outboard engines are used to move through if there are no fishermen targeting large catfish or largemouth yellowfish holding along the reeds on the deeper sides of the river.  
The inflatable’s have been individually designed each with attachments to take small electric,  2,5 and 5hp outboard engines . Outboards are rarely used however as most fishing trips are carefully planned for each day and worked (drifted) downstream.  Flat decks make it easy to stand and cast for between three and four fly fishermen per raft depending which size raft is used. It can take between 6 and 8 people with camping gear. It is not a requirement to make distant or long casts either from the rafts or from the banks as 'short shots' are sometimes more productive for the smallmouth yellowfish. Generally, smaller tributary rivers are easier to fly fish (although they generally require more hiking). Rewards from the larger rivers can come in impressive packages though. Including the size of the fish.