For you guys in the states, here in NZ we have a quota management system , whereby it illegal for anyone to sell fish unless you have a commercal fishing quota. It kind of works and our fisherys are healthy for it.

The blue fin Tuna are targeted during March April by tuna long line boats for export to japan, however Iam led to believe that the fat contect drops post spawn and the fish are not considered exportable at this time of year.
BHSQUID PM me I live in Pihia and can either give you some options on soem of our local charter boats or possibly shoot you out to Cape Brett for a jig on some of our Yellow tail kingfish, My boat definitly wont accomodate the whole family (4.2 m) but is well appointed safe and reliable