The advantage to becoming a country parson would give him freedom to pursue his natural history studies and his zeal for hunting. However, an unforeseen opportunity precluded Darwin's plan of becoming a clergyman. In 1831 after his student days in Edinburgh and Cambridge, Darwin found work on a survey ship, HMS Beagle as naturalist. The round-the-world journey lasted almost five years. Darwin spent most of these years investigating the geology and life of the lands he visited, especially South America, the Galapagos islands and Pacific coral reefs.