it helps with the currents cos then you dont have to blow them up as big, as has already been posted when shark fishing we tend to set the depth and then run our ballon of 1kg line leader and then with the pressure of the fish pulling down/across it tends to pop the ballon. if not then just have a gaff ready and once it is close enuff just go whack and pop she goes. here are some links to different rigs that can be used.
Im not sure what the regulations are on using the break free float rigs up there but i have heard that u cannot use them in certain places. apparently the turtles eatem.
Hamish