A little over a week ago my wife and I had a few days on Waiheke to celebrate our tenth wedding anniversary. We rented a car on the island and stayed in an apartment at Onetangi. The weather was fabulous and we had a great time. We didn't do much, but one day we walked from Cowes Bay Road to Waikopua Bay and then around the rocks to Man-O-War Bay and looped back along the road. The view from the eastern end of Waiheke across to Coromandel was fantastic. The second day we walked from Oneroa around the coast past Island Bay to Matiatia and then back to Oneroa. The first part of that walk is all vineyards, most of the rest is spectacular rocky coastline. That loop would be a good day trip since you can start and end at the Matiatia ferry and stop in Oneroa for refreshments. We ate out at Charley Farley's in Onetangi (good), Te Motu Vineyard (good, but surprisingly we were the only guests the whole time we were there), and the Lazy Lounge in Oneroa (also good).