general of the Department of Antiquity and Fine Art, claimed all of the artefacts for the National Museum and submitted a report requesting the recovery cease due to the "devastation of the two wrecks". An engineer from the Regia Marina (the Italian Royal Navy) surveyed the site to determine the feasibility of recovering the two ships intact. The engineer concluded that the only viable way was to partially drain the lake. In 1927 Benito Mussolini ordered to drain the lake and recover the ships. With the help of the Regia Marina, the Italian Army, industry and private individuals, an ancient Roman underground water conduit linking the lake to farms outside the crater was reactivated. The conduit was connected to a floating pumping platform on 20 October 1928 and the lake level began dropping. By 28 March 1929, the water level had dropped , and the first ship (prima nave) broke the surface. By 10 June 1931, the prima nave had been recovered and the second ship (seconda nave) was exposed. By this time the water level had dropped more than with over 40,000,000 m3 of water removed. As a result of the weight reduction, on 21 August 1931, 500,000 m3 of mud erupted from the underlying strata causing of the lake floor to subside. Work ceased and, while the risks of continuing the project were debated, the lake began refilling. As the seconda nave had already partly dried out, the submersion caused considerable damage. On 10 November 1931, the Minister of Public Works ordered the project and all research abandoned. On 19 February 1932, the Navy Ministry, which had been a partner in the recovery, petitioned the Prime Minister Mussolini to resume the project. Joining with the Ministry of Education they received permission to take over responsibility and pumping to drain the lake recommenced on 28 March. Around this time a small boat was found, about long. The boat had a pointed bow and a square stern. It had been loaded with stones in order to sink it. It is believed to be contemporaneous with the ships. Due to technical problems, the seconda nave could not be recovered until October 1932. A purpose-built museum constructed over both ships was inaugurated in January 1936. Construction Both vessels were constructed using the Vitruvian method, a shell first building technique used by the Romans. Step 1: construction of the profile. Step 2: construction