It's all glittering luxury yachts and big money when the Hamburg International Boat Show kicks off for the 50th year this week. But all too often the shiny decks and other details on such boats are made from rainforest woods, while the planet's green lungs are disappearing fast. Boat builders argue there's no alternative to hard-wearing tropical woods like teak, but in Norway some say there is.

Report: Lars Bevanger