Generating the world's highest tides, Canada's Bay of Fundy is a marine wonder. Sarah Marshall is swept away.

An enormous wave crashing against imaginary shores, a whale's breath is one of the most soothing sounds in the ocean - and it's cause for excitement in the Passamaquoddy Bay.

"There she blows!" cries our skipper Mackie Greene, pointing to a humpback cruising through waters packed with leisure vessels on a sunny weekend in Canadian maritime province New Brunswick.

Whales are a regular sighting along these Atlantic coastlines, but this year, more humpbacks, finbacks and minkes are visiting - all attracted by the movement of herring - and word has quickly spread.

"I've never seen so many boats," admits Mackie, a rakish, shy man with a tuft of moustache resting on his upper lip. During winter months, he earns money as a lobster fisherman, but in summer his vessel is used for daily whale watching tours. Having not had a day off since the start of the season, he survives on cookies, candies and a passion for wildlife.

In the Bay of Fundy, a body of wild water dotted with emerald-green islands, communities have learned to live with the sea, bowing to its strength and benefitting from its bounty - but never underestimating the power it holds. Mindsets and landscapes have largely been shaped by the phenomenal tides - the highest in the world - with more than 160 billion tonnes of seawater flowing in and out of the bay twice a day.

But like so many places on our planet, friction between nature and people is growing as greater pressure is placed on natural resources - particularly when it comes to fishing.

A battle to save the whales

Based on ancient methods for catching herring, circular wooden weirs loop around the shores of Campobello Island, occasionally trapping bigger mammals with their one-way system. More dangerous are fishing nets, entangling many whales for up to weeks at a time.

Eager to help, Mackie set up the Campobello Whale Rescue Team with his best friend Joe Howlett. "I love the whales," he implores, showing me some of the tools he's designed to help cut whales free. "We can't do everything, but we can do our bit. When we free them, they usually swim away quickly, but sometimes the humpbacks breach. They're so happy and thankful to be free."

Although rewarding, the job is fraught with danger; last year Joe was killed while attempting to rescue a North Atlantic right whale. Operations were suspended for some time, but last month, Mackie's team made their first successful release - a humpback mother and her calf.

"That felt good," grins Mackie, who still quietly mourns the loss of his friend.

On Campobello, an island kissing the US border and chosen as a holiday retreat by former President Franklin D. Roosevelt, I meet Moira Brown, a leading researcher on the North Atlantic right whale - the world's most endangered whale with a population of just 525. With no calves spotted yet this year, their future hangs in the balance.

The Bay of Fundy is a critical habitat for the mammals, although this year, they have shifted slightly further north to the Gulf of St Lawrence. Moira has been instrumental in canvassing the Canadian government to impose restrictions on shipping lanes, to avoid ship strikes. She admits very little is still known about the right whale and encourages tourists to look out for their distinctive V-shaped blow and callus-covered rostrums; any sightings can be registered on free app Whale Alert (whalealert.org).

Don't let lighthouses fade away

The Bay of Fundy is one of the few places in the world where whales can swim past your doorstep, a regular occurrence in the largest island Grand Manan, a 90-minute ferry journey from St Andrew's on the mainland and operating in its own little world.

Houses are covered in cedar shingles, stained blue-grey by the sea air, and lobster buoys in a rainbow of colours are strung up like bunting along picket fences licked by magenta fireweed.

An octagonal lighthouse built in 1860, Swallowtail, in North Head, is a great place to spot tail flukes and acrobatic seals.

About six years ago, when Ken Ingersoll and his wife Laurie Murison discovered the iconic building might be torn down, they intervened and purchased a 25-year lease on behalf of the community. But only after protesting to authorities. "It was like Frankenstein stuff; we were all carrying pitchforks," recalls Ken, as we approach the lighthouse along a wooden boardwalk, built with a government grant.

"We had 14,000 visitors last year, coming day and night to sit and relax," he says, proudly pointing to benches fashioned from disused lobster cages, angled towards the sea. "I was here at 3am the other morning and I bumped into a group of people. I put a pot of coffee on and we sat up talking until 7am."

Ken has been working on Swallowtail with his friend Chris Mills, a former keeper who once manned a nearby lighthouse perched on a rocky, wind-lashed outcrop known as Gannet Rock.

"I miss the sound of that crashing surf," reminisces Chris, who's wearing a T-shirt decorated with an illustration of his former home. A similar image is inked on his forearm; with Gannet Rock due to be torn down, the faded tattoo - and his cherished memories - could be the only associations Chris has left.

Ken hopes to claim the lighthouse's lamp for Swallowtail. The tower still serves as a beacon of safety for sailors caught in tidal rips, and a functional fog horn proves to be an essential instrument in these parts.

As if on cue, fog curls across the Bay of Fundy - as expected and almost as regular as the tides. Wisps swirl and tumble, settling overnight into a thick, blank fuzz. It could be a cause for irritation, but Maritimers have learned to appreciate these white-outs and have even named a summer music festival in its honour - Fog Fest.

Mopping up mermaid tears

Fortunately, by the time I reach Deer Island for my kayak tour with Seascape Kayak Tours, visibility has returned. A small car ferry trundles back and forth from L'Etete, where another community-rescued lighthouse gleams white against the lapis-blue sky.

The absence of any wind makes my paddle gentle, allowing me time to watch sea eagles swoop for fish and listen to a pod of synchronised porpoises puff like pistons on an aquatic steam train. Caught in a heat haze, the distant Wolf Islands quiver and levitate above the horizon, melting into a milky soup.

We pull ashore for a picnic of wild raspberries and foraged beach peas, followed by games of stone skimming and a hunt for mermaid tears. Softened and shaped by rough waves, the small pieces of washed-up glass twinkle like jewels in a pirate's chest - coveted ruby and sapphire drops being the hardest to find.

Folklore suggests the tears are shed through sadness, but I prefer to think they come from joy.

Because although Maritimers and marine mammals are beset by challenges, the sea forms a bond stronger than any glue, and inhabitants share one thing in common - an ability to weather storms, no matter how big.

How to get there

  • For more information on visiting New Brunswick, go to tourismnewbrunswick.ca.

  • For more information on visiting Canada, go to uk-keepexploring.canada.travel.