Following graduation from Cambridge in 1831 with a Bachelor of Arts degree, Darwin was clearly more interested in biology and geology than he was in a clerical career. Fortunately, John Henslow was able to help him secure a berth on a British Navy mapping expedition that was going around the world on what would ultimately become a nearly five year long voyage. Initially, Darwin's father refused to allow him to go but was eventually persuaded by Charles and even agreed to pay for his passage and for that of his man servant on the journey. They sailed two days after Christmas in 1831 aboard the survey ship H.M.S. Beagle with Darwin acting as an unpaid naturalist and gentleman companion for the aristocratic captain, Robert Fitzroy. Darwin was 22 years old at the time, and Fitzroy was only 4 years older. The Beagle was a compact 90 foot long ship with a crew of 74. There was little space, even for the captain. Darwin shared a cramped 10 X 11 foot cabin with two other men, a cabin boy, and their belongings. Because of the Beagle's design and small size, it was generally thought by naval men that it was ill suited for the rough seas it would encounter, especially at the southern tip of South America. Darwin frequently suffered from sea sickness on the voyage. Fortunately, he was able to spend most of the time on land exploring. In fact, he was at sea for only 18 months during the nearly 5 years of the expedition.