The painting is based on a real attack that took place in Havana harbour in 1749. Brook Watson was a 14-year-old orphan, serving as a crew member on a trading ship. While swimming alone in the harbour, he suffered multiple attacks by a single shark. On its first attack, the shark bit off a chunk of flesh from Watson's right leg below the calf; on the second attack, it removed his foot at the ankle. The crew of a small boat, who had been waiting to escort their captain to shore, fought off the shark and rescued Watson. His leg was amputated below the knee, but he went on to live a full life, including a term as Lord Mayor of London. The attack is the earliest shark attack to be fully documented.