We anchored pretty well but the current was as strong as I have seen it. We chose to continue - mistake #1.  We put out pull ropes on each side the boat and backward rolled, hanging onto the pull rope and using it to pull us to the anchor line.  Down we went and the viz was excellent.  At the bottom the anchor had been dragging in the sand and had stopped just short of  a ledge in the reef.  The anchor had piled a good deal of sand in front of it.  We swam along the anchor tracks in the sand but after a short swim I found the current too much and went back to the anchor.  Wayne came back shortly after.  We then headed across to the reef and from there could see the southern end of the wreck.  We followed the line of the wreck along the flattened hull and up to the boiler.  Mistake #2 - we didn't run a spool out from the anchor (and I carry 2 of them).  We went around the front of the boiler and to the large anchor.  This is where I hit the 50.0m depth.  Turning here we headed back past the boiler and back along the side of the wreck.  Wayne was on the east side, I was on the west side.  At the end of the wreckage we could not see any sign of the anchor,  I thought it was more west, Wayne thought more east.  Either way we were well out of time and had to ascend blue water.

Blue water ascents are not at all easy, with no reference at all.  My profile below shows the challenges we faced. It's not pretty, with several descents when we should have been ascending. To avoid being separated we used a short rope to attach our selves together.  At 21m we swapped to 50% Nitrox and I shot an SMB.  This helped quite a bit with controlling our ascent and in hind sight I should have shot it a lot earlier.  We completed our deco obligations and surfaced carefully.  We could not see the boat but were well well south of the boat.  Later we found we had drifted 1.5m south of the wreck site.  We figured we would swim across the current towards the coast, with the full expectation that a passing bot would see us and render help.  It would be quite a while before Marine Rescue Solander recognised we were missing.  After a few minutes a boat came past and came around close.  Two young men helped us get our gear into their small boat . no mean feat given it had no ladder.  To add to the embarrassment my spool unwound while I was getting my wing & backplate off and it had to be wound back up around my SMB.    Finally back on the boat and it had not moved.

Wayne had to pull the anchor up from 50m, with the 9lb weight and lift bag attached it took quite a while to get it up.  Finally we could rest and reminisce about the adventure.  At least we were safe -we did the right thing, knowing that in this area of Sydney we would be easily found on the surface, even if we had drifted right across Botany Bay.