SIEV meaning in Governmental ?

Suspected Irregular Entry Vessel (SIEV) was the operational term used by the Australian Defence Force and Australian Coastwatch for maritime vessels which appear to be attempting to reach Australia clandestinely.

The legal context was of vessels that were entering Australian waters without authorisation. Previously the term 'Suspected Illegal Entry Vessel' was used. These boats are almost exclusively carrying asylum seekers who have departed from Indonesia on the final leg of a journey which started in countries such as Iraq, Afghanistan and Sri Lanka after paying "people smugglers". During Operation Relex, 12 SIEVs were intercepted. Four were forced back to Indonesia, and three sank.

SIEVs were given numerical designations. The vessel involved in the children overboard affair was the SIEV-4. The vessel that sank in 2001, killing 353 asylum seekers (mostly women and children) was designated by the press as SIEV X (a temporary operational term used by Coastwatch prior to designation, the SIEV-X often referred to in the press was reported not to have been detected prior to sinking).