Despite the risks involved, at some stage during your stay in Bukit Lawang you might be tempted to have a go at tubing - the art of sitting in the inflated inner tube of a tyre as it hurtles downstream, battered by the wild currents of the Bohorok. The tubes can be rented from almost anywhere for about Rp2000 per day, or your losmen may supply them for free. There is a bridge 12km downstream of the village, where you can get out, dry off and catch a bus back. If you're not a strong swimmer, consider tubing on a Sunday, when lifeguards are dotted along the more dangerous stretches of the river around Bukit Lawang.