If you want to employ 7 or more crew, you must have Approval in Principle, and provide crew with a copy of your Approval in Principle letter to include with their work visa applications.
If you want to employ fewer than 7 crew, you don't have to apply for Approval in Principle, but you must complete a 'Supplementary Form for Crew of a Fishing Vessel' for your crew to include with their work visa applications.
Supplementary Form for Foreign Crew of a Fishing Vessel (INZ 1213) PDF 309KB