KEY POINTS:
The two boys leaning off the port bow of Dream Weaver had their eyeballs out on stilts. Only a metre below them, almost within touching distance, a dolphin mother and newborn calf were riding happily in the catamaran's bow-wave.
On the starboard side a mother and daughter - my daughter and grand-daughter - were spellbound watching three adult dolphins of varying size jockey for the best position.
For 8-year-old Kate it was a thrill just to see dolphins close at hand. "They're really beautiful. And they swim so fast. Even the baby is faster than the boat."
But for Victoria, her mother, the best part of the experience was the chance to find out about the dolphins.
"The people on the boat were really cool, and it was great to learn from them about dolphin behaviour, and to be able to ask questions while watching the dolphins perform right in front of us."
We were on the Hauraki Gulf with Dolphin Planet - which has one of only two Department of Conservation permits to take tourists to see the Gulf's marine mammals.
Around us was a playful pod of about 20 common dolphins, obviously enjoying themselves frolicking with Dream Weaver, occasionally breaking away to perform a few aquatic acrobatic moves.
"Most Auckland people don't seem to realise there are dolphins in the Hauraki Gulf," said the boat's marine educator Laura Torre.
"They think you've got to go somewhere like the Bay of Islands to see marine mammals. But they're right here on our doorstep."
Not only are there dolphins in the Gulf but there are plenty of them. A group from Henderson North School which went out on Dream Weaver found themselves in the middle of a pod of around 500.
They're also fairly easy to find. Dolphin Planet offers customers a free pass to go on another trip if they don't find dolphins and, says manager Jennie Cowan, "we've only had to do that once, and that was because of bad weather".
And the Gulf has other marine mammals as well as common dolphins. Torre says in the 10 months she has been taking trips she has seen several Bryde's whales, the smaller bottlenose dolphins, orca, long-finned pilot whales and "once I saw a New Zealand fur seal".
While we were watching the antics of the common dolphins Cowan was keeping a weather-eye out for the spout of a Bryde's whale. "We often find them associated with feeding dolphins. We see them on maybe 50 per cent of our trips in summer."
"They're not demonstrative, so you can really only locate them when they spout, and it's my job to keep a lookout while everyone else is enjoying the dolphins."
Unfortunately we didn't encounter any Bryde's whales - which grow to around 14m and weigh up to 26 tonnes - possibly because two of the species were found dead in the gulf over the weekend as a result of accidents with ships.
But we did get to spend over an hour with the common dolphins as they played round the boat.
Initially they were quiet, apart from the panting noise when they came up for air, but after a while they started talking to each other so the spectators leaning off the bow could clearly hear the squeaks with which they communicate.
Needless to say the calves were a particular focus of attention, Torre exclaiming delightedly that "they're so cute," while pointing out the markings which showed that two or three were newly born.
A couple of times the dolphins located food and surged away, porpoising high out of the water as they gathered speed, then combined to round up a school of fish for a community meal.
This brought the added bonus of gannets taking advantage of the dolphins' work by dive bombing into the compressed mass of fish for an easy meal.
Later, when the dolphins rejoined Dream Weaver, Torre was able to point out the silver fish scales being dropped by the bow-riding animals as a sign their hunt had been successful.
There was plenty of other life on the Gulf, too, with lots of gannets - several looking too stuffed with fish to fly - big flocks of shearwaters, terns, petrels and a couple of little blue penguins.
Sadly one of those penguins, which drifted past while we were anchored for lunch off Tiritiri Matangi, was dead.
"Is it real?" asked a young man swimming round the boat at the time, evidently suspecting it might be from of the vast collection of stuffed toys Torre uses as teaching aids when taking out school groups.
A huge enthusiast for the marine environment, and marine mammals in particular, Torre loves the chance to share her knowledge and passion with school groups or - as in our case - youngsters with their families.
On the voyage back from the Gulf she kept my grand-daughter and another girl of the same age hugely entertained doing puzzles and games about dolphins.
"I just think we're so lucky having the Hauraki Gulf next door to us that I want to tell everyone about it," she says.
"Maybe if we learn to understand and enjoy what it has to offer then we might become better neighbours."
