What is Sydney Harbour anti-submarine boom net?
[[Image:WatsonsBay0192.JPG|thumb|right|250px|The anti boom net winch house foundations is all that remains. The net went from here and all the way across to the other side (pictured in the distance).]] [[Image:WatsonsBay0205.JPG|thumb|right|250px|Entrance to Green Point Anti-motor torpedo boat defensive Battery.<ref>{{Cite web |url=http://www.woollahra.nsw.gov.au/__data/assets/pdf_file/0003/9156/DCP_-_Watsons_Bay_Part_3_Precincts_O-T.pdf |title=Watsons Bay Part 3 Precincts |access-date=2008-01-08 |archive-date=2007-08-29 |archive-url=https://web.archive.org/web/20070829051101/http://woollahra.nsw.gov.au/__data/assets/pdf_file/0003/9156/DCP_-_Watsons_Bay_Part_3_Precincts_O-T.pdf |url-status=dead }}</ref>]] The '''Anti-submarine boom net''' was used to stop enemy [[submarines]] entering [[Sydney Harbour]] during [[World War II]]. The net went all the way across the harbour from Green Point, Watson's Bay to Georges Head on the other side. The boom was part of the Sydney Harbour defences which also included [[artillery]] batteries and [[Warship|patrol boats.]] ==History== In January 1942, the [[Australia]]n defence forces began to build the anti-[[submarine]] boom net; it was finished in August 1942. For more than three years, entry by [[boat]]s, [[ship]]s and [[Ferry|ferries]] into [[Sydney]] [[Harbour]] was through one of three different gates that were a part of the anti-submarine boom net. On 31 May 1942, during WWII, three [[Japan]]ese submarines tried to get into the harbour. The first submarine to try and come in was the M27. [[Lieutenant]] Jahai Chuma was the man in charge of this submarine. The M27 followed a Sydney ferry through the gate on its way to [[Manly, New South Wales|Manly]], but it got caught in the western end of the net's middle section. Lieutenant Chuma, tried to free his submarine by using a special tool that cuts metal, but this only made things worse. By 8:30pm the [[watchman]] for the Maritime Service Board, James Cargill, went to see what was happening. He used a boat to row across to wh