These guys are heading out from Auckland on Saturday. But to be honest the diving around Auckland is pretty poor. As Andy suggested try Goat Island for a shore dive or any of the operators at Tutukaka that go to the Knights. My favourite is
PKDive (Im allowed to say that aye Andy).
You could also try posting at
www.sod.co.nz to see if anyone is interested. There are a few of us from there heading up to Tutukaka for some wreck diving on Monday if you are still around then.