In 2008, "Adelaide" was the second ship of the class to be decommissioned, in order to offset the cost of an upgrade to the other four vessels. This ship was to be sunk off Avoca Beach, New South Wales as a dive wreck on 27 March 2010, until an appeal to the Administrative Appeals Tribunal by protest groups led to a postponement of the scuttling until additional cleanup work was completed. Despite further attempts to delay or cancel the scuttling, "Adelaide" was sunk off Avoca on 13 April 2011.