From a tourist blog. I was looking for information on this event and found this:

http://www.virtualtourist.com/travel/Afr...Falls-BR-1.html

"
For this trip there are only the two of us and Future, the guide. It isn't a jet boat trip like we know it from New Zealand and Fiji, this is more of a wildlife cruise than an adrenalin trip. With its shallow hull, the jet boat can navigate narrower channels than any other river craft, thus getting closer to wildlife. The area is full of colourful birds, and we see some monkeys frolicking in the trees. I desperately want to see a crocodile, and right on cue there are three resting on the banks of the river. Hippo can be seen everywhere in the river. It used to be that hippos kill more people in Africa than any other animal, but these days that title goes to the mosquito.

On one of the islands there is a herd of five elephants drinking down by the river's edge. Future navigaes the boat right up to the bank to get really close to them - so close that we can almost touch them - but in my eagerness to climb on to the front of the boat to get even closer, I make a noise and scare them away.

Fortunately there are a few more around the corner, and they seem totally oblivious to our presence as they are ahving a drink and a sand bath on the banks. Lunch is provided for us - with Zambezi beer of course - on an island in the middle of the river. Chicken, ham, rolls, salad, potato salad and fresh fruit for dessert.
"

I guess he was lucky in this case they were "scared" off.