Hi Craig - sorry, in New Caledonia at the moment.
I was using a Coral Vipwr and Blue Lagoon so rods were under 8 feet in length. I do think a longer rod would be advantageous there as depending on the waves, the boat can't always get you within range.
There are no secrets to long casting with GT gear. It's technique. Length of the rod and lighter braid but as I always say, it is all a compromise.