oldoberon,
The small search area highlighted on the map is where The Ocean Shield is now ( Marine tracker website) and that's what they've highlighted for the sonar buoys. If my eyes are correct.
Also interesting on Marine tracker is the warship HMAS Toowoomba is already coming back from Exmouth probably for supplies to the other ships. Nice to a have a speedy supply ship. I'm wandering if these promised German Submersibles capable of 6000m are on board. Also shows HMS Echo heading towards Ocean Shields search zone as well.
Live Ships Map - AIS - Vessel Traffic and Positions - AIS Marine Traffic