Team members of PlanetSolar wave with flares as they achieve the first around-the-world tour with only solar energy, on May 4, 2012 in Monaco. The biggest solar boat ever built progressed through Atlantic Sea, Panama canal, Pacific Ocean and is back to Mediterranean Sea through Suez Canal. More than a year and a half after leaving Monaco, the 31-metre (102-foot) Swiss catamaran, skippered by a Franco-German-Swiss team of five members, completes the 30,000 miles of this first world voyage only powered by solar energy. The Swiss-flagged boat, which was built in Germany and cost 26 million USD, is topped by 500 square metres of black solar panels, with a bright white cockpit sticking up in the centre. AFP PHOTO/ VALERY HACHE (Photo credit should read VALERY HACHE/AFP/GettyImages)