Furniture built from rainforest hardwoods like teak or mahogany has become a mark of environmental insensitivity. But if lumber companies harvested the perfectly preserved trees left under water by dam construction, they could increase the supply of such woods without endangering tropical habitats. So says Gary Ackles, president of Aquatic Cellulose of Vernon, B.C., who has developed a mechanized "aquatic lumberjack" to recover these valuable commodities far more quickly and safely than human divers could. Aquatic Cellulose is harvesting 1,800 square kilometers of trees from a Brazilian reservoir.

The system consists of a robotic arm controlled from the deck of a barge; the operator maneuvers the arm underwater with guidance from digitally enhanced video and real-time acoustical imaging. The robot arm can cut through a 1-meter diameter tree in 15 seconds and haul logs to the surface from up to 35 meters under.