Hire one ($10 hour) or two ($20 hour) - there are good beaches and places to explore near here (Buckland's beach, Tamaki Estuary). I can email a picture of them if required. Ideal 2.5 hour from high tide and not too windy weather.
PS I have a trailer (you might have your own or you might have a towbar), I have some wetsuits (you might have your own), child and adult life jackets, 2 X paddles. I can transport them to a beach near here for you ($10 hour to cover my time and petrol).