In English language there is almost nothing that can satisfy Felix C's requests. Adm. Maugeri's memoirs, which have already been recalled, were indeed written by an American journalist after some interviews with him, and are not trustworthy at all.
Commander Marc'Antonio Bragadin was an officer of Supermarina (the High Command of the Regia Marina) during WW2, so his "The Italian Navy in World War II", Naval Institute Press, 1957 (it was reprinted by Arno Press in 1980), is the only book written by an Italian Navy officer published in English language, but it's not a book of personal memoirs.
In Italian language I suggest Adm. Raffaele De Courten's memoirs "Le memorie dell'ammiraglio De Courten (1943-1946)", USMM, 1993. Aldo Cocchia, already mentioned, is excellent too. I would suggest also adm. Alberto Da Zara's (the winner of the Action off Pantelleria during the Battle of Mid June 1942) "Pelle d'ammiraglio", Mondadori, 1949.
Then, of course, there are adm. Giuseppe Fioravanzo's and adm. Oscar di Giambernardino's books, but they are purely history books, without any autobiographical aspect.