Thanks for replies and links,
Normally such a fish would get unhooked boatside. But was a good first for me to tag.
I have a 150L tank in the Wahoo floor with constant fresh water filling, Once a GT is slid into tank they are fully supported in water and stay very calm. Measured in tank, tagged and then can be released, as soon as they see the bottom they go for it!!
Anyways, hopefully the water will clear up and can get amongst em next weekend.
S