Ophelia turns on Sydney search

By Carmelo Amalfi
CYCLONIC seas have hampered initial efforts to find HMAS Sydney off WA, according to search leader David Mearns' March 6 report.
"Tropical Cyclone Ophelia, a category one storm packing gale force winds, decided to change course and turn directly for our location," Mr Mearns said. "Whilst it is hard to find a silver lining as a cylcone bears down on you, I am grateful that Ophelia is not as severe as the Western Atlantic hurricanes I am used to.
"Still we are facing certain weather downtime, which although expected and budgeted for, is hurtful to our progress at this early stage in the search. There is an old saying that the sea doesn't give up her secrets easily and it appears Ophelia has dropped in to remind us of that."
But he said the first twist was, "a particularly cruel one" - the sonar towfish was experiencing problems, affecting the imagery of the seafloor while trailing the survey ship at the end of a 6000m towline.
Another immediate problem involved an electrical cable that was found to be nicked, allowing water to penetrate the cable and cause short circuiting. It was replaced.
The search resumed on Saturday, March 8.
Mr Mearns said the search area was extremely large: "In marine terms it measures roughly 1,800 square nautical miles ... or about 2.5 times larger than the ACT. It is by far the largest area I have ever set out to cover in a shipwreck search project."
He said another way to appreciate the scale of the search was to put yourself in a location on land and imagine a box that extends 39km in every direction.
The land will have areas that are flat and sandy, rocky and hilly. Within that area, the search team is looking for an object about 171m metres long and 17m wide (HMAS Sydney).
"Finally, imagine the land you are searching is flooded with several thousands of metres of water and this will give you an idea of the challenge we face," Mr Mearns explains.
He said while it was frustrating to have had such an unlucky start to the search, he was confident better weather was due and that problems with the sonar towfish would be resolved.