A scenic, secluded bay at 121 Great Barrier Rd in Oneroa on Waiheke Island, Sandy Bay holds a 4.5 rating from 111 reviews, with visitors praising the swimming, kayaking and fishing. Note that you'll need your own transport to reach it, as reviewers report no buses come this way.
Waiheke's lesser-known bays reward a little planning. There are no shops or facilities at the small beaches, so bring everything with you, and check the tide before you settle in, as many bays shrink quickly at high water. Rocky points and channels are where the fish hold — snapper and kahawai most often — with dawn and dusk the productive hours, and a kayak opening up water no shore fisher can reach. In warm shallows, stingrays are a familiar sight; give them space and they glide off without trouble.
Quiet enough that regulars describe it as a bay the tourists haven't found, Sandy Bay is Waiheke at its most peaceful.