There has been only one vessel of that name in the Royal Navy, a fishing trawler already bearing that name was hired into service in September 1939 for use as a minesweeper and kept her commercial name.
590 tons (gross)built at Selby in 1939, after conversion, during which she was armed with 1 x 4in gun, she was based at Aberdeen. Took part in the Norway campaign of April/May 1940 during which she was sunk by German air attack off Narvik 21 May.

Why Cape Passaro? She was originally built and owned by the Hudson Fishing Company of Hull and they tended to name their trawlers after Capes, so there was a large number of them, Cape Argona - Cape Chelyuskin - Cape Palliser etc., etc., On being taken over by the Navy they all retained their original names. She would have been named after the cape in Italy.

Incidentally the R.N. would not have objected anyway, because of the Battle of Cape Passaro (or Passero) of August 1718 when Admiral Sir George Byng destroyed 22 Spanish ships.