Another link that might be of interest, with the history of this boat.
http://images.google.co.uk/imgres?imgurl=http://www.regiamarina.net/subs/submarines/davinci/images/6959.jpg&imgrefurl=http://www.regiamarina.net/subs/submarines/davinci/davinci_us.htm&h=66&w=122&sz=5&hl=en&start=27&tbnid=Y6m0y0xGob85mM:&tbnh=48&tbnw=89&prev=/images%3Fq%3Dsunken%2Bsubmarines%26start%3D20%26ndsp%3D20%26svnum%3D10%26hl%3Den%26lr%3D%26sa%3DN
Cheers
Al
