Suddenly, right before my eyes, the water seethed and out popped a slim, black, shiny, bewhiskered head. A young seal emerged from its morning swim, gave an inquiring glance as if to ask, "Are you looking for me?" and climbed rather clumsily out of the water and on to a rock.
Tonga Island, part of Abel Tasman National Park, in the northwest corner of the South Island, is home to a small herd of seals which are well used to humans kayaking, cruising or even swimming in their midst.
I had been hoping to meet one of the seals while we were kayaking along the park's spectacular rocky coast, because I knew from previous encounters in Fiordland that they will often come right up close to check you out.
Better still, Daniel, our kayaking guide, had said the young pups in this neck of the sea were sometimes so curious they would actually climb on board and come for a short ride.
But on this occasion we didn't see any seals while kayaking so I had to be content with viewing them later from the deck of the catamaran Abel Tasman Voyager, though as a bonus, I also spotted one while I was walking the coastal track.
As that indicates, one of the special features of the Abel Tasman park is that because it is a long, thin strip of coast, with small towns at either end, there are many ways to enjoy its attractions - by kayak, launch or on foot - and there are a lot of ways to get access - by road, sea or air - and they're all impressive.
Even the bus journey from Nelson to Kaiteriteri, the main base for visiting the park, offers an unusual mix of scenery and entertainment.
Our bus driver sucked my wife in completely when he told us that on the left-hand side of the road we'd see one of the South Island large brown kiwi which, unusually, forage in daylight. It was indeed large, very large, and made of fibreglass.
The driver also pointed out a crashed flying saucer in a field with its green pilot phoning home from an old-fashioned red telephone box nearby; he explained that the local custom of using stones to write names in the mudflats alongside the road originated as a memorial to a young man killed in an accident; and he told the lovely tale of Hamish the white heron who spends his winters in the Smokehouse Cafe at Mapua bludging food from customers.
The park itself is a similar mix of magnificent landscapes and delightful stories.
For instance, it may be named after the Dutch explorer Abel Tasman, who in 1642 became the first European to sight New Zealand, but Tasman himself never set foot there and didn't think much of the place, calling the spot where he anchored Murderers Bay after four of his crew were killed by local Maori (funnily enough, in 1857 it was renamed Golden Bay to highlight the discovery of gold).
And Kaiteriteri may have been selected by the British newspaper The Guardian as one of the top five beaches in the world but the name given it by local Maori has the rather unromantic meaning of "hurry up and eat".
Still, it's not an entirely inappropriate name, because on most summer days the beach is a seething mass of activity as visitors gobble down snacks before heading off in kayaks, pedal boats, hire yachts, runabouts and sight-seeing vessels to explore the park.
We first headed off in kayaks, which is a wonderful way to check out the golden beaches and rocky headlands of this stretch of coastline. In a kayak you can pull ashore at any of the bays to stretch your legs and do a little exploring or nose up close to the headlands to study the rich seabird life or marvel at the extraordinary rock formations.
The most interesting formation we came across was Split Apple Rock, just outside the park boundary, which does indeed look like a split apple. But from Daniel we learned that according to Maori tradition the rock is a taniwha's egg broken open during an argument between Tangaroa, god of the sea, and Tane, god of the land. In a cave nearby he showed us lots of smaller taniwha's eggs waiting to hatch.
An even more relaxed way to explore the park is by boat, in our case on the Abel Tasman Explorer, a purpose-built catamaran with a ramp extending off the bow to make it easy to load and unload passengers off the beach.
What could be better than sitting back, sipping a cool beer and listening to the commentary on all the beautiful places floating past.
Many of the place names were given by the French navigator Dumont D'Urville, who mapped this section of coastline during visits in 1823 and 1827 - Adele Island, honouring his wife; Coquille Bay, named after his first ship; Astrolabe Roadstead, after his second ship; Observation Cove, where he checked the accuracy of his measurements through star sights - making him a much a more suitable person to have the park named after him than the fleeting Tasman.
Other names recall some of the activities carried out along the coast before there was a park. At Bark Bay in the 1870s members of the Huffam family collected the bark from beech and rimu to extract tannin. Apple Tree Bay recalls a small orchard established by early farmers. At the Tonga Quarry you can still see the remains of the quarrying operation which produced granite for the steps of Nelson Cathedral.
The third way to explore the park is on foot. We walked a section of the track from Onetahuti Bay to Medlands Beach - an easy stretch but a great cross-section of what the full Abel Tasman Coastal Track offers over three to five days. Our walk started with a fanfare thanks to the arrival of two fine fat kereru at the Tonga Quarry, ended with a refreshing swim in the warm, clear waters of Medlands, and along the way offered magnificent seascapes, inviting beaches, spectacular waterfalls and rivers, some lovely regenerating bush and superb camping sites dotted with tents.
Back at Kaiteriteri, after being collected by the Explorer, we bumped into another pioneer, 70-year-old John Wilson, founder of Wilsons Abel Tasman, the company which almost by accident pioneered trips into the park.
The boat that originally took passengers into the park was wrecked in a storm in 1977 and Captain John started being asked to carry people on his home-built launch Matangi. Then the Wilson children found themselves often showing visitors around the park area surrounding the family bach at Torrent Bay.
Next there were trampers keen to overnight at the bach and at his wife Lynnette's family homestead at Awaroa. Gradually it all grew into a successful tourist operation.
These days, however, the business is mainly run by the Wilson children.
Getting there: Air New Zealand offers up to nine flights a day from Auckland to Nelson with fares starting from $95 per person one way. Phone 0800 737 000.
Where to stay: The boutique four-star Grand Mercure Nelson Monaco offers a range of accommodation including apartments, with rates from $129 per night. For bookings and information visit accorhotels.co.nz or phone 0800 44 44 22.
What to do: Wilsons Abel Tasman offers a range of activities in the national park. Ring 0800 223 582.
Further information: To find out about the national park see doc.govt.nz.
Jim Eagles was a guest of Air New Zealand, Grand Mercure Nelson Monaco and Wilsons Abel Tasman.