We had just set off and were paddling slowly along Barton Broad – a picturesque expanse of water fringed by reeds – when I looked up at that vast, endless sky. The sun, not yet fully risen from its slumber, was throwing pink streaks across its canvas, which only seemed to accentuate its, well, bigness. I was wistfully soaking up this picture, when: "There, there!", a loud whisper startled me from behind, as my co-paddler and husband, Christian, started paddling at double speed. "That was definitely one up ahead, by the riverbank, just ducked under". Damn, missed it.

This is a challenge you face when on an otter-spotting canoe trip on the Norfolk Broads: the wild landscape is so stunning that it's hard to keep your eyes on the water. Thankfully, we had Mark Wilkinson, or rather the Canoe Man, as our guide. Along with Tarka – his beloved 117-year-old cedar wood canoe, the oldest working canoe in the world – and his excitable springer spaniel, Mr Darcy, Mark spends most of his waking hours on the broads and knows them like the back of his paddle, including the popular hangouts of these elusive creatures. Barton Broad was just the start. Our day trip would take us down the River Ant, across the River Bure to Fleet Dyke, all the way to the South Walsham Inner Broad, a journey of almost six miles.

The typical way to explore the broads – a network of rivers and lakes covering 115 sq miles across Norfolk and Suffolk – has long been the self-drive motor cruiser. But they're missing a trick. "With the canoe," Mark explained, "you can explore narrow channels and shallow waters that are inaccessible to motorboats. You see wildlife that you would never see otherwise."

We paddled silently through Barton Broad's tangled dykes, flanked by tall reeds. A pair of Canadian geese swooped overhead. A Cetti's warbler sang out. Every now and then, Mark would reel off interesting facts about this species and that, with the odd tale thrown in for good measure. Canoeing and storytelling – it was as if Mark was born to do it; surprising then to think that eight years ago he was in his 20th year selling pensions. But, he'd always been an avid outdoor enthusiast – ever since being in the Scouts as a youngster – so he bit the bullet, swapped pensions for a paddle and started running canoe day trips throughout the Norfolk Broads. They were a huge hit, so Mark thought, why stop there? He soon developed overnight canoe trails, with exclusive use of wild campsites along the way, and next year he plans to open five tipi camp sites along the River Bure.

It was barely 11am by the time we reached the River Ant, and we'd already seen a brilliant array of wildlife; the majestic marsh harrier, countless moorhens, even a pair of great crested grebes performing a courtship dance.

As for the otters, it was Christian: one, me: nil. Zero. Nada. I wasn't worried though. At South Walsham Inner Broad, our final destination, a resident pair of otters – and their cubs – had been spotted all week.

So how common are otter sightings in the broads? As common as they've ever been, according to experts. In the early 1980s, Norfolk's otter population was dwindling to the point of extinction. "As recently as ten years ago, if you spotted one otter a season you'd be over the moon", Mark said. But numbers have risen rapidly over the past decade; in the past month, Mark has seen around ten. Considering we were almost in the prime otter-spotting season (May to June), the odds were in our favour, I reasoned, binoculars poised.

We continued winding our way downstream, as the river twisted and turned through some of the most scenic countryside in Norfolk. It was utterly tranquil, and apart from a few near misses with overhanging alder trees, I felt like a paddling prowess (even though Christian insisted he was doing most of the work).

After a quick pit stop at Ludham to refuel on brie and bacon sarnies at the Wayfarers tearoom, it was back on the water, along the narrow Fleet Dyke to the vast South Walsham Outer Broad, which in turn lead to the private – and impossibly serene – Inner Broad.

As we crept slowly along the bank – lined by goat willow trees and silver birches – a kingfisher flitted across the water in front of us, while the booming call of a bittern rang out overhead. Suddenly it dawned on me – I actually wouldn't care if I didn't see an otter. This was enough.

Then Mark spotted them. A series of mudslides and large clusters of empty swan-mussel shells – sure signs of otter activity.

We paddled on, as silently as we could against the gentle current. Then, up ahead, a movement in the water. That was no moorhen. We drew closer. There it was – the flat-shape head, the swish of a long sleek tail. An otter. We watched it glide effortlessly through the water, before it submerged below, leaving a trail of bubbles. It may not have been a cub, but it was worth the wait.

All too soon our journey, and day, came to an end. All that was left was to dock, bid the otters – wherever they all were – farewell and take one last look at that big, big sky.

The Canoe Man (01603 499177; thecanoeman.com) offers day otter-spotting trips from £20 adult, £12.50 children. 38 St Giles in Norwich (01603 662944; 38stgiles.co.uk) has doubles from £140 per night, including breakfast