Major dive hubs (Auckland, Tutukaka, Paihia/Russell, Wellington, Picton/Waikawa, Kaikoura, Te Anau/Manapouri) have rental gear and air fills, but remote regions have fewer options and limited shop hours. Plan exposure protection carefully: many divers use 7mm wetsuits year-round outside Northland summer, and drysuits are common for the deep south. Bring adapters if you have strong valve preferences, and travel with your own computer and mask if fit matters. Pack a warm layer and wind shell for surface intervals, because boat decks can feel cold even when the water is manageable.