River rafting
If your clients want to ramp it up a level, then you might wish to recommend white-water rafting, with an experienced operator.
The most popular of these trips are generally on the perennial Orange or Vaal rivers, but there are other rivers in the country where your clients can go white-water rafting.
One of the best of these is the Ash River, close to the town of Clarens in the Free State, a three-hour drive from Johannesburg. Because the Ash River is fed by water from the Katse Dam in the Lesotho highlands, rafting is possible here all-year round (unlike many other rivers that are seasonal).
The Umkomaas River in KwaZulu-Natal is a seasonal white-water destination that also offers opportunities for multi-day trips, as is the Doring River in the Cederberg in the Western Cape.
Another exceptional experience, is a multi-day river-rafting trip. This is an authentic African outing, allowing your clients to sleep under the stars and drift down pristine stretches of river.