USS Yacona (SP-617), built in 1898 in Scotland, started her life as a civilian steam yacht. She was called Cem and Amélia in her early years and only later renamed Yacona, the name she had when she was acquired by the US Navy in September 1917. During the period when she was called Amélia, the 527 gross ton vessel was owned by D. Carlos, King of Portugal between 1889 and 1908, who was an oceanographer and used her on his research voyages. She was known as Amélia III, being the third of four yachts owned by D. Carlos sharing the same name.