Marianne and I have had the chance to experiment with many sports while travelling, but never game fishing.

When we were invited, then, to go fishing on the Zambezi River - for tiger fish no less - we leapt at the chance. And it turned out to be more adventurous than we'd expected.

Firstly, we'd be sleeping on a luxury houseboat, the Nguni Voyager, moored on the Chobe River, near its famous game reserve. And we saw elephants, hippos and other game from our beds and from the comfort of the boat's leather couches while having tea and home-made cake.

Cruising on a houseboat is an idyllic way to watch wildlife and unwind: you're in pristine wilderness far from anywhere and anyone.

This trip was a dream come true for the couple on board with us - the "tigers" were the magnet for him; the birds for her - and they were charmed by the stylish "floating lodge".

The Nguni Voyager has five en-suite cabins and five speedboats, each with a guide, to take guests game viewing or fishing.

On our first morning in pursuit of tigers we woke up at sunrise, downed coffee and rusks, and joined our guide, Laskey Simalumba. Laskey, 26, looked like a safari model in his khaki outfit and shades against the early morning rays.

We motored out into the current and into the Kasai Channel, which links the Chobe and Upper Zambezi rivers, and crossed small rapids to a spot near the bank.

Once we were anchored, Laskey baited our lines with chunks of silvery fish and we cast them out, following his instructions. We got better at casting but our initial efforts had some funny mishaps, like when Marianne's fish bait hit me in the chest and once my hook went flying the wrong way.

Not long after our lines starting drifting out, I got a bite. The suddenness and power of the pull when the fish started to run knocked me off balance and I nearly let go. Instead, I hung on with Laskey as back-up and started to reel it in.

All the way, the fish was bucking and pulling, and finally we got it into the net and onto the boat. The first tiger fish was a youngster of only a few pounds but, from the force it exerted, it felt like a shark to me.

Now I know why tigers have a reputation for being swift and strong fighters. We admired the fish and its teeth and quickly let it go, and it swam away with a flick of its tail.

That marked the start of a successful fishing trip, thanks totally to Laskey's experience and knowledge of where to find them.

Next, Marianne caught a fish, then I caught another and we kept on getting lucky under Laskey's instructions. Within an hour or two, we had landed and released five large tiger fish. (Our second morning prior to our departure was less intense, with us catching three in total.)

We were surprised at how much fun the fishing turned out to be: the suspense of waiting for a bite and then the struggle to reel in and land a fish. Many were skilled enough to eat the bait and not get hooked.

Focused on the fishing, we had one of our narrowest wildlife escapes ever. We heard a loud crashing noise and saw an adult hippo with an open mouth charging us from a few metres away.

Luckily we had reeds between the hippo and ourselves and were on a boat with a motor, not our usual canoes. Laskey fired up the boat and we roared to safety.

"That's the most aggressive hippo I have ever seen," said Laskey, who grew up on the nearby Impalila Island and has been a safari guide for four years. He thought it must have been a mother with a baby.

Marianne's survival instincts kicked in and she thought about which way to jump rather than taking photos (her camera was around her neck) when we saw the huge mouth approaching us.

We both got a jolt of adrenaline, firing up our appetites for brunch.

The feast that awaited us when we got back to the Nguni Voyager exceeded our hunger.

Freshly baked muffins and bread, muesli, fruit, cheese, cold meats and a full English breakfast or omelettes, and filter coffee. The coffee and food were great and the omelettes filled us up for the day - or at least until tea time.

Time slows down on the boat, with the hours seeming infinite. We soon relaxed on the Voyager, which started to move after brunch.

From our cabin, we could watch the crocodiles sunning themselves on the bank. From the lounge, we could spot dozens of birds on the floodplains, from raptors like fish eagles to many types of kingfishers, herons and flocks of bee-eaters.

In the late afternoon, we boarded a much bigger speedboat designed for game viewing and sundowners and slowly moved along the banks, getting close to herds of elephants and other wildlife.

Marianne and I have been game viewing from the top of elephants and horses, and boats allow you another kind of proximity that is on the animals' level. We got right up to a drinking elephant and saw other game, like buffalo, baboons and rock monitors.

As the sun turned the river shades of red, we returned to the Voyager with its upstanding crew and were treated to another meal of many courses: tomato tarts, then steak and baked dessert.

After dinner, I lay on the top deck under a dazzling array of stars, talking to the Voyager's new owner, Rod Hering.

Rod, a keen wildlife photographer, and his wife bought the boat for retirement one day - he wanted to run a game lodge - and taking over the Voyager realised this dream. He may even get into tiger fishing.

• Claire Keeton and Marianne Schwankhart were guests of the Nguni Zambezi Voyager. For more information, phone 011 791 3101 or 083 726 4091; e-mail info@ngunivoyager.com or visit www.ngunivoyager.com