Throughout his entire journey through the Lower Orinoco the traveler faces only one danger: the natural rafts formed by drifting trees uprooted by the river. Woe to the canoes that at night strike one of these rafts of tangled lianas and tree trunks! When Indians wish to attack an enemy by surprise they tie several canoes together and cover them with grass to make it seem like a tangle of trees. Today Spanish smugglers do the same to avoid customs in Angostura.