Heading to Ripapa Island, exploring the fort and learning history, seems fitting for a Waitangi Weekend.
Stopping in Lyttleton upon the return for lunch, either at Lyttleton arms or Fishermans Wharf (Let me know your choice of location).
Will need to book own ferry for date, $30 for an adult, $15 for 5-15 year old. (https://blackcat.co.nz/ripapa-island/). Event starts 30 min before ferry leaves Lyttleton for Ripapa.
History and culture
Tucked close against the southern shore of Whakaraupō (Lyttelton Harbour), the small island of Ripapa was an ideal site for a fortified pa for Ngāi Tahu and later, a fortress to defend against possible Russian attacks.