It was named after Jacinto Caamaño, commander of the Spanish exploration ship Aranzazu which had been on the coast in question in 1792. Captain Frederick C. Learmonth of HMS Egeria[1] who surveyed the Zayas Island[2] officially named the strait Caamaño Passage.
See also
Caamaño Sound, another body of water in British Columbia that is named for Jacinto Caamaño
^"Aristazabal Island". BC Geographical Names. Named in 1908 by Captain Learmouth, HMS Egeria, while making a survey of Zayas Island, after Lieutenant Commander Jacinto Caamaño, commander of the Spanish corvette Aranzazu, on this coast 1792.