I stood on the boat's back deck, gripping the tiller and peering down at lambs and ewes grazing in green pastures far below me. Pigeons flew beneath the boat and soared across the misty blue hills. "Sheep ahoy," shouted the captain beside me. An answering "Aye aye" came from the distant bow as our crew rushed to look over the side.

It was early autumn. My wife, Barb, and I, with two Scottish friends, were cruising Britain's Llangollen Canal in rural England and Wales. We had rented a classic narrowboat, which was providing both transportation and housing for the week. Now we were steering our boat through a thousand-foot water channel, crossing high above the Dee River valley on the largest aqueduct in the United Kingdom. Behind us spread the rolling farmlands of Shropshire; ahead rose the Welsh mountains. And far, far below us a flock of sheep was ignoring our nautical passage overhead.

Barb and I, and our friends Ruth and Jimmy, had no experience operating a boat. Anywhere. The thought of navigating our elongated houseboat through myriad locks, tunnels and aqueducts was daunting — even more so when our boat hire company spent only a few minutes "orienting" us before handing over the keys.

"Don't worry," the man assured us, "in a week you'll be experts."

What saved us was the leisurely pace on the canal. Top speed on U.K. canals is a mere 4 miles per hour, and most of the time we kept our boat's diesel engine quietly chugging through the verdant countryside at a slow crawl. The tow path, originally intended for horses who pulled 19th-century barges up and down the canal, is now a public recreation trail popular with strollers and bicyclists. In fact, on our first cautious day of cruising, we were overtaken by an elderly gentleman with a cane, limping along the canal-side path and eventually disappearing into the distance ahead.

At such low speeds on narrow canals, collisions are common but seldom do damage. In our first afternoon afloat, we managed to run aground in midstream, scrape several bridge abutments and collide with a tree. No matter. The sturdy craft are like fairground "bumper boats," bouncing gently off canal banks, tunnel walls, even other watercraft. Every narrowboat we saw carried the inevitable scars, for most of the traffic on the Llangollen canal was piloted by vacationing landlubbers as inexperienced as ourselves.

A quirky houseboat

Finding our way was easy. A map from Heron Maps, Ltd., showed everything from aqueducts, locks, bridges and overnight mooring places to historic sites and — perhaps most important — pub locations. Cruising slowly against the 1-mph current, we had ample time to commune with herds of curious cows and unimpressed sheep in pastures along the banks, while noisy mallards and wild cranes took flight at our approach. Jimmy and I took turns being "captain" at the tiller; Barb and Ruth — our genuine first mates — sat up in the bow, watching for approaching traffic as we steered around bends, through tunnels and under bridges.

We barely traveled a mile up the canal that first day, mooring for the night alongside a country inn. Ruth and Barb brewed tea in the galley and brought it up on deck where Jimmy and I were playing guitar and English concertina. Another boat tied up near us, its crew coming over to enjoy the music; they invited us into the pub for a few friendly pints, and we all had dinner together.

Our narrowboat is a quirky houseboat unique to Britain, designed for the U.K.'s 2,200 miles of navigable waterways. Its wood-paneled cabin is comfortably equipped — central heating, flush toilet and shower, double bed, kitchen galley with stove, microwave, fridge and all utensils, and a main cabin with satellite TV and benches that can form a second double bed — all within its 47-foot length.

Narrowboats can stretch 70 feet or longer and might have two or three bedrooms, two baths, perhaps a cozy wood-burning stove, or even a Jacuzzi. Whatever the length, narrowboats can be no more than 6 feet, 10 inches wide so they can pass through the 7-foot gates of the locks that enable canals to climb and descend across the rolling countryside of England, Scotland and Wales.

A beautiful, dramatic canal

At the dawn of the Industrial Age, canal systems spread rapidly across the face of Europe and the British Isles. But rail and highway development soon followed, moving cargoes faster and — eventually — cheaper than canal barges. By the end of World War II, commercial traffic on the British waterways was no longer competitive, and many canals fell into disuse.

In the 1970s, Britons began to realize the recreational potential of their canal system. Tow paths where horses once hauled barges were turned into walking and bicycle trails; crumbling canals and bridges were renovated by enthusiasts. Old barges were converted and new ones built as houseboats for holiday makers or year-round residents. Outfits providing rental craft for tourists proliferated.

The Llangollen Canal on which we were traveling lies about 50 miles northwest of Birmingham, crossing the border from western England into North Wales. It is one of the most beautiful parts of the canal system, and possibly the most dramatic. An 11-mile section of canal below the town of Llangollen has been declared a World Heritage Site by UNESCO.

Barb and I had visited the U.K. many times — even lived there for three years — and thought we had explored every corner of Great Britain; but this was a new experience. Our boat meandered quietly through pastures and woodlands, hidden lakes and wildlife preserves, past farms and villages, country inns, castles, historic homes and lovely gardens. We could stop where and when we wanted, to walk or picnic or shop or just sit on the deck and play music. At night we tied up at free and convenient mooring rings found in scenic places, near pubs or in towns.

Despite our inexperience, the first do-it-yourself lock operation went smoothly. I threaded the boat successfully between the lower gates and into the dripping stone chamber; Jimmy, Ruth and Barb closed the gates and cranked open the valves to let water rush in. Slowly the boat was lifted more than 6 feet to the next level of the canal. My crew opened the upper gates and stepped nimbly aboard as the boat moved out toward a second lock, a half-mile ahead.

Later in the week, we would pass down through these same locks on our way back from Llangollen town.

Our first aqueduct carried us 70 feet high over the Ceiriog Valley near the town of Chirk, on the border of England and Wales. It is wide enough for only one boat at a time, but there was no oncoming traffic as we bumped gently along the sides of the thin channel. At the end of the aqueduct, we entered the Chirk Tunnel. Our boat was equipped with a headlight and horn, and we used both as we chugged through, occasionally bouncing off rock walls in the inky darkness.

We emerged into sunlight at the north end of the tunnel, where there are public moorings. From there, a half-hour's walk leads to Chirk Castle. Built in 1295, Chirk is the last Welsh fortress from the reign of Edward I that is still lived in today. The castle welcomes visitors, and has a cafe, beautiful gardens and a farm shop selling local produce.

Bridge by bridge, aqueduct and tunnel, we were developing our steering skills. After Chirk, we navigated the Whitehouse Tunnel without a bump, and a few bridges later, tied up for the night on a quiet, wooded stretch of the canal. Through the trees, across a valley, we could see the imposing structure of the Pontcysyllte Aqueduct awaiting our approach the next day.

The aqueduct, built in 1805, stands on slender masonry pillars 126 feet above the River Dee, and carries a boat-width trough of water more than a thousand feet across the valley. On one side there is a walking path with a railing; on the other side there is nothing. From the deck of our boat, it was like cruising along the edge of an 11-story building.

Beyond the aqueduct, the canal cuts across the slope of a mountain, with high cliffs on one side and steep drop-offs on the other. In places it narrows to a single boat-width, and crew members have to walk ahead to warn oncoming traffic. It was late in the afternoon when we came to the end of canal navigation at the town of Llangollen.

Welsh resort town

Nestled among the hills bordering the Dee River Valley, Llangollen is one of the most popular resort towns in Wales. Its winding streets are lined with flowers, the shops and pubs are delightful, and an old-fashioned steam railway, museums and horse-drawn barge tours keep tourists entertained.

Every year in July, the Llangollen Eisteddfod, a six-day music festival, attracts audiences from around the world, and traffic on the canal system peaks. Offseason, canal traffic is uncrowded, the weather is cool, the skies are dramatic with sunbeams and cloud shadows and boat hire is cheaper. Our narrowboat, fully equipped and fueled for the week, cost about $115 per night per couple. We made breakfast and supper on board, and took our main meal of the day at pubs along the canal that cater to narrowboat traffic with convenient moorings where visitors can tie up.

After five days on the canal, locks and bridges no longer daunted us. We turned downstream from Llangollen with newly acquired confidence, retracing three days' cruising in a matter of hours. The next day we crossed back into England, passed our starting point at Maestermyn Bridge, and tied up for the night at the market town of Ellesmere. Here we shopped for groceries, enjoyed award-winning steak pies at the Black Lion Inn, and spent the only rainy hours of the week in our boat's cozy cabin, playing whist and singing old Scottish songs.

Our last full day afloat, we set out through the Ellesmere Tunnel into a placid landscape of wooded copses and glassy lakes graced by swans and herons. At midday we turned the boat at Whixall Moss Nature Reserve, and headed back toward our starting point, steering precisely now through bends and under bridges. Along the canal, fishermen lifted their rods and picnickers raised their wine glasses to salute our passage.

Toward evening we tied up by the Narrowboat Inn, just downstream from the Maestermyn marina where we were due to return our boat the next morning. In seven days' cruising we had traveled 50 miles, negotiating locks, aqueducts, tunnels and bridges, without noticeable damage to the boat, ourselves, Wales or England. That night in the pub, we celebrated fulfillment of that first-day prediction — we had become "experts" at last.

St. Paul writer Jack Maloney is the author of "The Wee Mad Road: A Midlife Escape to the Scottish Highlands."