Man behaving boldly: Martin Clunes in wild New Zealand

Life is laid back on the antipodean islands. But it's not without excitement. The actor tells Nick Kirby about his adventures on pristine beaches and overgrown slopes between shoots for his latest television drama people and places

New Zealand has pulling power. It's a place that had always enchanted but evaded me. So the thought of spending six weeks filming on location there was enough to get me signing on the dotted line immediately.

I arrived with my wife, Philippa, and our seven-year-old daughter, Emily, and was quickly introduced to the Kiwi way of doing things. The driver booked to collect us wasn't at the airport, as our flight was half an hour late. Rather than wait,he just left, which is somewhat indicativeof New Zealand's laid-back attitude.

The North Island, where I was based, is very Maori and my time there, as a result of the film's story, mirrored this. I play Ian Bennett, a museum curator from London who has the task of travelling across the globe to handle a repatriation claim for an ancient artefact from a small Maori community. Prior to the trip, I knew almost nothing of Maori culture and traditions but I made the conscious decision not to educate myself on the subject. The whole story, after all, is about a journey of discovery and it was nice to be on that same journey with the character.

The Maoris' ancestors hailed from Polynesia, and members of the community all descend from one god or another. They can actually trace that lineage, and there's a tremendous amount of respect shown towards each other and more than just tolerance displayed from the European population.

We had Maori cultural advisers on set and, consequently, blessings at every turn. Before we could shoot a funeral scene, everything had to be squared with the gods and that involved a song and a prayer. It was important that nobody remained in the realm of death. The beliefs are very much alive and applicable to the way people live; they seemed to connect in a way some other faiths don't appear to.

We were all struck by Bethells Beach, a picturesque and secluded spot where we spent some time filming. There are several other beaches in the area – one of which was a location for the film The Piano. A small village is some distance away, so the welcome feeling of isolation isn't compromised.

Although Bethells Beach is only a 40-minute drive from the busy streets of Auckland, it's completely off the beaten track. It's wide, quite tidal and there's a fabulous promontory of rocks on one side and beautiful sand dunes that form wonderful shapes. We shot a scene there where I had to ride a magnificent white horse named Shadow along the shore. Despite Shadow being no stranger to this show-business lark – his CV already boasts appearances in Xena: Warrior Princess and Hercules – I was keen to bond with him before the cameras started rolling.

Horse riding on sandy shores is always exciting and my family and I enjoyed the most fantastic two-hour ride along the beach and up into the hills beyond. After trotting along the shore we turned our backs on the open expanse of the water and continued through undergrowth and into pure wilderness, unaided by tracks of any kind. It was fabulous and not just because of the scenery; this was the first opportunity the three of us, all keen riders, experienced the thrills together.

Shadow and I got on well. Our friendship even survived a slight glitch on set when he bucked and threw me off his back. He had a friend along for company, a horse by the name of George, and as long as Shadow could see George he was as good as gold. Unfortunately for me, George wandered out of Shadow's eye line as the excitement of shooting a scene was building. It all happened so fast: the director shouted, "Action!" causing Shadow to leap up suddenly and before I knew it, I was back on my feet.

But what surprised me most about New Zealand wasn't anything as predictable as the warmth of the people or the sheer scale of the scenery, or even the amusing behaviour of the horses. It was the quality of the coffee. They take coffee seriously and as a result, it's absolutely outstanding – and I'm a European. Even on set we had a professional machine that made a truly amazing espresso. It's totally changed me. I was a tea drinker before and now I find myself desperately searching for that perfect cup all over Dorset.

My hectic filming schedule meant I only had one full weekend off – it wasn't the glamorous job I was promised – and so, much to my regret, I didn't see a fraction of the things I'd have liked to. Having said that, we enjoyed what could possibly be the best day trip ever. After jetting to Nelson, at the top of the South Island and spending the night in the most amazing farm-turned-lodge, we were collected the next morning by a helicopter that whisked us off to the coastal town of Kaikoura, the whale-watching hub of New Zealand. En route, we glided over dramatic and diverse landscapes from incredible green and deep valleys to barren hilltops and permanently snow-capped mountains. The frequent changes were bizarre and the farmlands below looked like a chequered tablecloth.

The Pacific Ocean was as flat as a pancake as we set sail. The trip was extremely well organised – they delivered sperm whales within about eight minutes of us embarking. I'd never seen these impressive creatures of the deep in the wild before and I was dying to catch my first glimpse. To my initial disappointment, and that soon changed, they looked like logs floating on the surface, with only the occasional spout confirming otherwise.

There's something the whales do, some movement or signal that tells the experts on board that they're preparing to dive and treat us to that famous "tail out of water" image. As that moment drew nearer there was a lot of photography going on. In fact, I was lying on the floor trying to get a low angle with a lens I'd brought four months previously, specifically for this one instant.

Pods of dolphins later appeared beside the boat and kept leaping out of the water playfully. While Emily was hypnotised by their frolicking, I was pleased to have spotted a lone albatross as it glided past the vessel. The safari didn't end there – we also drifted by a seal colony. They just stared back at us before continuing with whatever they were doing before we rudely interrupted.

Back on firm ground with seat belts fastened in preparation for the flight back, our pilot turned to me and said, "Is there anywhere you'd like to stop off at on the way home?" Quite remarkably choppers in New Zealand don't have to follow a flight path; they can just go wherever they like. The captain had done a lot of corporate flying for the Cloudy Bay winery, so he called ahead on his mobile to see if the visiting Poms could spontaneously drop in. We ended up ordering three cases.

Further exploring took me to Raglan, a small surfing town that's really rather hippyish. The area looks like the Cornish coast, although on a slightly grander scale, and at the town here you'll find lots of cafés, lots of bars and most importantly, lots of waves.

The water was chilly, but living on the south coast of England has hardened me to that, so I waded in. The waves weren't giant in scale but at my level of surfing – and I've had numerous lessons and accept that I'm never going to change that level – it's all ski lifts and no skiing. You go struggling out there, time it right, pop up for seven seconds, if you're really lucky, and that's it. I get more of a rush on a shopping trolley. Surfing? I'm over it.

Adrenalin is clearly big business here. I recall walking down the street in Auckland one day, looking up and seeing someone hurtling to the ground above me. The idiot had just bungee jumped off the Sky Tower, the tallest free-standing building in the southern hemisphere, and I couldn't help but wonder why.

People in New Zealand love their white-knuckle activities. If they're not skydiving from 12,000ft or white-water rafting, they're catapulting themselves here, there and everywhere; and yet afterwards, they always look like they've done everyone else a favour. Without feeling even a tingle of temptation to tie an elastic rope around my ankles and follow suit, I ventured up the Sky Tower for nothing more than the impressive views.

Apparently, New Zealand is prone to the odd earthquake. Had I known this, one particular evening would've made far more sense. I was sitting in my room in Mollies, my charming Auckland hotel, when everything suddenly started shaking. It wasn't enough to set off the car alarms but there was an eerie sense of silence that lingered afterwards. All the birds fell quiet and cicadas ceased their usual nocturnal performance. I considered ringing down to reception but presumed they'd just tease me and so thought nothing more of it. The next morning, however, the newspapers were ablaze with reports of the biggest quake in 30 years.

But that's New Zealand for you: full of surprises. Now, where's my coffee?

Further viewing 'The Man Who Lost His Head', starring Martin Clunes, is on ITV1 tonight at 9pm