SeaLink Ferry - Cheaper than flying; does not run every day and make sure you take it to the port you want, I’d suggest Tryphena as opposed to Port Fitzroy. Takes about 4.5 hours, I left Auckland on a Sunday morning and returned Tuesday evening.
Hitchhiking - Hitching is easy and safe on the island; I only waited for more than three cars before being picked up once.
Medlands Beach - I stayed right near here; the isolation adds to the beauty. Ocean is cold, but walk up and down the beach; there is even a small cliff to climb up!
Mermaid Pools - Just over the hill from Medlands sits a tidepool. I jumped in with no one around, just me and the ocean. Watch the timing of the waves for a few minutes first. This and the rest of the island really showcases the beauty and power of nature!
Kaitoke Hot Springs - A track leads to some hot springs buried deep within the island. Emphasis on hot, watch your feet. The walk builds up to the springs. Also, do not put your head under due to possible amoebic bacteria!!
Medlands Beach Backpackers (Great Barrier Island) - Secluded hostel located on Great Barrier’s eastern side.
Bring all your food from Auckland. Hardly any restaurants and everything is expensive.