SIEV X stands for Suspected Illegal Entry Vessel X. SIEV is the acronym used by the surveillance authority for any boat that has entered Australian waters without prior authorisation and the X is a designation where a tracking number has not or is yet to be assigned, in accordance with Australian Government orders. It is also used by author Tony Kevin, to refer to a dilapidated Indonesian fishing boat that was en route from Sumatra to Christmas Island carrying over 400 asylum seekers. It sank in international waters on 19 October 2001, just south of the Indonesian island of Java, killing 353 people. The tragedy was politically controversial in Australia, as it occurred during an election campaign at a time when asylum seekers and border protection were major issues.