Thank you both. Yes, I intend to contact ANAIM but as I say language is a challenge. I will more or less only get one chance and as has been pointed out my Google translated Italian doesn't come across very well.
Lefa, good to hear that I am not alone. Yes I am interested in the SDVs, but also the dry subs (Maritalia for example) and semi-subs, explosive boats (historical) and fast boats. In fact everything water-related. I will cover the WW1 and WW2 history for context but the fresh content of the book will be cold war era.
Re keeping secrets. Yes the American's are least secret, or rather, they keep the fewest secrets. For sure there is stuff they will not share and/or I will not ask. The British SBS (as distinct from the SAS) are much more secretive, although less so than COMSUBIN. However, the degree of access they've given me is, I think, unprecedented. I feel very privileged. The SBS generally apply a 30-year rule and even then there is older stuff that they will not share, or if i figure out I cannot or will not write about.
I would expect something similar with COMSUBIN. By them agreeing to help, I'd limit my scope to the time period and content that they are willing to share and would check the draft past them before publishing.