'Eco-boats' clean-up Rio ahead of 2016 Olympics
7 January 2014 Last updated at 09:54 GMT
'Eco-boats' are being used in Brazil as part of a massive clear-up operation ahead of the 2016 Olympic Games.
The green catamarans are patrolling the polluted waters of Rio de Janeiro's Guanabara Bay alongside wooden fishing boats.
Tons of garbage and raw sewage flow daily from sludge-filled rivers into the bay, where the Olympic sailing and wind surfing events are to be held.
Wendy Urquhart reports.