One-hour rafting trips led by enthusiastic multilingual guides descend Class III or IV rapids, taking in some lovely gorges before ending up back in San José de Maipo. Allot about 2½ hours in total for the briefing, outfitting and drive upriver to the starting point. Helmets, wetsuits and lifejackets are provided, and there are lockers to store your belongings.
The river is made up of a series of mostly Class III rapids with very few calm areas – indeed, rafters are sometimes tossed into the water. Still, it's less hazardous than when the first kayakers descended in the 1980s and found themselves facing automatic weapons as they passed the grounds of General Pinochet's estate at El Melocotón (the narrow bedrock chute here, one of the river's more entertaining rapids, is now known as 'El Pinocho,' the ex-dictator's nickname).