I squeal in excitement as one dolphin keeps eye contact with me as we circle together. She wriggles her graceful grey body in a response so joyful I could almost burst.
So I wriggle and squeal more and suddenly the dolphins are leaping from the sea, somersaulting through the air, then splashing down into the water around me.
I feel brushed by luck and rich beyond the wealth of anyone in a mansion on the hill for having experienced this day of dolphin bliss.
But having fallen in love with the dolphins, I worry about them. Over the past few years, they often seem more hungry than playful - and then the jet-skiers start harassing them.
That's why I'm celebrating the precedent set by the Court of Appeal decision supporting marine protection in the Bay of Plenty last week.
A tiny hapu from Motiti Island was backed by Forest & Bird in a six-year court battle – and won.
The story of the Motiti Rohe Moana Trust begins back in 2011, when the container ship MV Rena hit Otaiti or Astrolabe Reef, spilling 350 tonnes of oil.
An exclusion zone was placed over the reef and eventually, it became alive with marine life.
A group of Motiti residents was troubled by seeing fish disappear and kina barrens return after the exclusion zone was lifted – so their battle for marine protection began.
Last week's court decision means regional councils must use the Resource Management Act to protect biodiversity and habitats in the ocean the same way they protect native birds and bush on land.
I'm hoping the decision will lead councils around New Zealand to create new marine protected areas.
Some fishing folk around Tauranga are lamenting the likelihood of new no-take areas, but marine protection now means more fish in the sea for the future.
More fish and healthier seas also mean a better chance our dolphins will survive.
Only about 450 bottlenose dolphins currently live around the North Island, and smaller numbers can be found in a few areas down south. Maybe we can spare these beautiful beings, who bring joy wherever they swim, a few fish.
A tragic wasteland lies under the sea, after decades of over-fishing and destructive fishing methods, such as bottom trawling.
I often snorkel past rows of people fishing over kina barrens around Waiheke's coasts and my heart sinks.
The only mature fish I see are a few parore and spotties that eat kelp and seldom take a bait.
Again and again, I notice fishers hauling up undersized fish on their lines. It seems pointless, hooking and sometimes killing fish before they even have a chance to reach legal size.
Kina barrens are spread around the coasts of most of the North Island. Snapper and crayfish would eat the spiky sea urchins, but humans have gobbled up so many snapper and crayfish that kina breed like an undersea plague.
When I was a child, kina hid under rocks, but now they cluster in easy sight, with more than 10 per square foot covering the rocks in some places.
The kelp that floats to and fro in the waves is steadily retreating as kina munch their way through its slippery branches. It's sad to watch the destruction of a stunning underwater forest, with pink coralline seaweeds and orange sponges on the rocks beneath.
Thankfully, a few forward-thinking conservationists won battles to get a few areas set aside for marine reserves decades ago.
After more than 50 years of protection, Goat Island Marine Reserve on the east coast just north of Auckland is a form of heaven. Snapper longer than my arm laze past, staring into my eyes with a look of ancient wisdom that always takes me by surprise.
Snorkellers can spot hundreds of fish with an amazing variety of forms and features within half an hour in the marine reserve. In many other places, you can swim for an hour and not see a single fish.
The ocean absorbs about 25 per cent of the carbon dioxide in our atmosphere, so it plays an important role in reducing the impacts of climate change. If we don't care about healthy oceans for the dolphins or rebuilding fish stocks, maybe that's a fact worth thinking about.
Rose Davis is the communications officer for the Royal Forest & Bird Society of New Zealand
