Beware, out on Lake Naivasha. The possibility that underground springs may feed the lake, its location on the floor of the Rift Valley, and its shallowness all combine to produce notoriously fast changes of mood and weather: grey and placid one minute, suddenly green and choppy with whitecaps the next. Boating mishaps are all too common and you should be sure your vessel has lifejackets and your “captain” and mate (don’t go out with only one crew) have radio contact with the shore, not just a dodgy cellphone connection. Watch out, too, for hippos, which can overturn a small boat easily if frightened or harassed. Although there’s no bilharzia in Naivasha, the hippos, the dense weeds, and the occasional sightings of crocodiles combine to offset any enthusiasm you might have had for a swim.