Rhet,
DI's most famous bit of Terra firrma, Wolf Rock, had some moose sized GT's living there.
Unfortunately, the "rock" is closed off due to the 'Grey Nurse Shark protection' debacle.
Fortunately, GT's do move/patrol, so it's still worth peppering the headland, though this time of year you are more likely to get the smaller 6-10kg models as Pete said, or yellowtail kingies and the odd jumbo tailor too.
Summer time is when it cranks for pelagics though it is still worth a go if the blue water is running past the headland.
Cheers
Aaron.