Historical documentation fixed the location of the Maple Leaf off Mandarin Point in the St Johns River (Figure 1). The vessel sank after striking a confederate torpedo on April 1, 1864 with the loss of four lives (New York Times April 13, 1864) The side wheel steamer was constructed in Kingston, Ontario in 1851 for service on Lake Ontario and the upper St Lawrence River. According to the original Certificate of Ownership (1851), Maple Leaf measured 398 tons burthen, 173.2 feet in length between stem post and stern post, 24.7 feet in beam, and 10.6 feet in depth of hold. Leased to the Federal Government during the Civil War as an Army transport in 1862, the steamboat operated on the Atlantic coast until lost. Efforts to find the wreck site began with a thorough review of historic documentation relating to the loss of the vessel and later salvage efforts. The most important source of information became the navigation charts of the river produced by the United States Coast and Geodetic Survey. The 1876 chart (Figure 2) identifies the wreck off Mandarin Point by name and the 1884 chart (Figure 3) depicts the wreck site marked with a beacon. The vessel posed a hazard to shipping and the U.S. Army Engineers awarded contracts to Roderick G. Ross in 1882 and 1888 to clear the wreckage (United States Army Engineers 1882, 1888). Following this work, navigation charts issued in 1888 and 1911 show the wreck site as a shaded area (Figures 4 and 5). By comparing landmarks found on these charts with modern charts and aerial photographs the approximate location of the site was determined and a search area defined. Field verification was not undertaken until the following year.