The former Australian Naval vessels, HMAS Swan and HMAS Perth were scuttled as artificial reefs off the Western Australian coast in 1997 and 2001, respectively. In addition, the former HMAS Hobart was sunk in Gulf St Vincent, South Australia in 2002.
All hydrocarbons, hazardous material and liquids, debris and as far as was practicable, all metals of environmental concern were removed prior to scuttling in accordance with the Environmental Management Plans (EMPs). This was undertaken to minimise the environmental impact as a result of heavy metal and petroleum hydrocarbon contamination…
Corrosion Monitoring and the Environmental Impact of Decommissioned Naval Vessels as Artificial Reefs, October 2004
The words “as far as was practicable” are not very encouraging when you are describing the removal of materials that cause cancer in humans and degradation of the marine environment.