Dianna, Are the family English or Irish? It sounds like one son was born on a trip or short term stay in Ireland. Some clues may be in the occupation of the father. Was he a mariner or soldier for example? If they went to Ireland and back, the name of the ship seems of little consequence. I'd list out family members and where they were in 1861 and 1871 census. As for Antrim births try http://www.irish-roots.ie/ Peter in Sydney