We spent two afternoons up at the bays. They are nicely sheltered and get a lot less wind than much of the peninsula.
It's a shame I'm not a better photographer, as my pics just don't do them justice. (I think you would need a serious panoramic lens for that.)
Other than being highly photogenic, it's also great for swimming, snorkeling, bird watching, hiking or finding a secluded cove to just hang out in. Also, though there are shells on the beach in some areas, for the most part it's just sand.
There is a small campground nearby, but otherwise the bays are very secluded.
Beach review #4: Matai Bay and Waikato Bay
Best use: Anything that doesn't require a lot of surf. (Bodyboarding possible)
Cool stuff: Apparently it's the best beach-access snorkelling in the far north. There is also pinnacle diving too.
I might have given this beach a 5 if the water wasn't so cold. We went snorkeling once in full wetsuits, but I was freezing in no time. Also, when we went it wasn't low tide, so it wasn't particularly interesting. The bay empties out quite a bit at low tide, so definitely better to snorkel then.
We've booked a couple of reef dives in the Bay of Islands a few days from now, should be interesting to see if I freeze or not!