In pictures: Getting food to Miskito Indians

"If the boats capsize, the food will go to the bottom of the river along with the crew," says Santiago Tablada, who is in charge of transporting and distributing the food.

The solution is to unload half the food before the boats reach the rapids, and have some 60 Miskito volunteers carry it for 2km through the forest until they reach the point at which the river flows calmly once more.

Progress is slow, with ankle-deep mud hindering the volunteers, and rain making conditions even more slippery. They travel in a line, negotiating fallen trees and fighting off insects as they go.