Got your PM mate, Henderson's is Henderson bay and you need to go right or if you have an inflatable go out to the reef, it to is off to the right you cant miss it, bit of a bugger if you miss the turn off.
Bucks is spirits bay, easy access and hammered but the fish are there if your patient, personally i would do the island best accessed at low tide you can fish both side and have taken many a goody out of there, some great night fishing to be had there as well and off the beach.
Karikari, well Matai Bay and walk but dont leave anything in the car, scrotes live here.
Hihi would be another spot i would go best in an easterly and again some fine fish there just gotta be patient.
hope that helps a bit, remember big baits and bigger bust offs the north has it all.
you just gotta put in the hard yards mate.