Plastiki will make 4-month , 8,000-nautical - mile voyage in Sydney . Ship is made of more than 100 plastic ##s . Expedition leader said he was inspired by a U.N. report on littering .
Plastiki will end 4-month , 8,000-nautical-mile journey in Sydney . Ship is made of more than 12,000 plastic bottles . Expedition leader says he was inspired by a U.N. report on littering .