Golden bay kayaks do guided and freedom kayak hire from tata beach. Fantastic area to kayak, including arches, seals etc and into wainui bay at high tide. For the abel tasman you can kayak from Marahau. Also kayaking trips from Kaiteriteriteri to split apple rock and beyond. For a day in the abel tasman I recommend a water taxi, kayak, walk package to see the maximum amount and enjoy the park from so many different angles. In nelson cable bay kayaks do a great trip in the marine reserve with caves, arches, seals. Also you can hire paddleboards from moana or kitesurf at tahuna beach and paddle around fifeshire rock. It is very popular and stunning on a day like todays stunning day.
I dont recommend kayaking in kaikoura so much - the seas are pretty rough. Only place I have ever got seasick in a kayak!
I have also kayaked Marlborough sounds. but the problem is there arent alot of bays to go into (private with baches mostly) and its a long way to the head of the bays around peninsulas.