Twice a day, the Bay of Fundy fills and empties like a lung. Somewhere around 160 billion tonnes of seawater move in and out with each cycle, more than the combined flow of every river on the planet, and at the head of the bay the difference between high and low water can exceed 16 m. Numbers like that are hard to picture until you stand on a wharf at Alma, New Brunswick, and watch fishing boats that were floating at breakfast sitting on bare mud by lunch.
This is a guide to reading them: where to go, what to look for, and how to use a tide table so that you arrive at the right place at the right hour. On Fundy, timing is the whole trip.
Why the tides are so high
The bay is a funnel about 270 km long, narrowing and shallowing from its mouth between Maine and Nova Scotia to the two arms at its head, Chignecto Bay and the Minas Basin. Its natural period of oscillation, the time it takes for water to slosh from one end to the other and back, is close to the 12 hours and 25 minutes between successive high tides. The result is resonance: each incoming tide reinforces the one before it, the way a swing gains height with each push. Elsewhere on the Atlantic coast the range is a metre or two. At Burntcoat Head, on the Minas Basin in Nova Scotia, the average range is about 12 m and the recorded maximum is 16.3 m, generally accepted as the highest on Earth.
The range varies with the moon. Spring tides, which arrive around the new and full moon, are the largest; neap tides, a week later, are noticeably smaller. When a spring tide coincides with the moon’s closest approach to Earth, the bay produces its most extreme days, and those are worth planning around.
Hopewell Rocks and the ocean floor
The Hopewell Rocks, about 35 km south of Moncton on the Chignecto arm, are the bay’s most photographed spot for good reason. Sandstone stacks, some of them 20 m tall and topped with a few clinging spruce, stand on a beach that is walkable for roughly three hours either side of low tide. At high tide the same stacks are islands, and kayaks paddle between them. The provincial park charges an entry fee that is valid for two consecutive days, precisely so that visitors can see both states. Staff post the safe walking window at the top of the stairs; respect it, because the water returns faster than a person walks across soft mud.
Our advice is to arrive about two hours before low water, walk the beach as it widens, then come back six hours later to watch the same ground disappear.
Fundy National Park and the Nova Scotia shore
Fundy National Park sits on the New Brunswick coast just west of Alma and covers about 207 square kilometres of Acadian forest, river valleys and a coastline of rock ledges and coves. Its trails, more than 100 km of them, include short walks to waterfalls such as Dickson Falls and longer routes along the shore where the tide dictates whether a beach exists. The park charges a daily entry fee, and its campgrounds fill early for July and August through the national reservation system. Alma, at the gate, is where we buy a tide table and watch the harbour drain.
Across the bay, the Nova Scotia side is quieter and, in places, higher. Burntcoat Head Park, on the Minas Basin about 90 km from Halifax, has a small lighthouse and a stairway down to the ocean floor where the record tides were measured. Cape Split, near Wolfville, is a 13 km return hike along a headland to cliffs where the incoming tide roars through a narrow channel below. At Joggins, on Chignecto Bay, the eroding cliffs expose fossil trees more than 300 million years old, and the site is inscribed on the UNESCO World Heritage list.
The tidal bore
Where rivers empty into the head of the bay, the rising tide does something strange: it reverses them. The leading edge of the flood, a wave that can be anywhere from a ripple to more than a metre high, travels upstream against the current, and behind it the river runs backward for an hour or more. This is the tidal bore, and it can be seen at several places. In Truro, Nova Scotia, the Salmon River bore passes a viewing park on the edge of town. In Moncton, the Petitcodiac bore was reduced to a trickle for decades by a causeway, then returned after the gates were opened in 2010, and now draws crowds to the riverfront. On the Shubenacadie River, rafting outfits run boats directly into the wave. The bore arrives at a predictable time, published to the minute, and is over in seconds. Be early.
Grand Manan and the outer bay
At the mouth of the bay the tides are gentler, but the water is deep and cold, and that draws whales. Grand Manan Island, reached by a car ferry of about 90 minutes from Blacks Harbour, New Brunswick, is 34 km long, cliff-edged on its western side and dotted with fishing harbours on the east. From July to September, humpback, fin and minke whales feed in the currents offshore, and the bay is the summer home of a large share of the world’s few hundred North Atlantic right whales. Sightings are not guaranteed, and the boats keep a careful distance from the right whales in particular. The island is also one of the best places in eastern Canada to watch migrating shorebirds in August.
Timing a visit with tide tables
Tide tables for the bay are published by the federal hydrographic service and reproduced by every visitor centre and campground office on the coast. Read them once and the trip plans itself.
- Look up the dates of the new and full moon for your month; the largest tides fall within a day or two of each.
- Note that the times shift about 50 minutes later each day, so a low tide at 9 a.m. on Monday is around 9:50 on Tuesday.
- Plan Hopewell Rocks, Burntcoat Head and any beach walk around low water, and Cape Split or a kayak trip around high water.
- Tide times differ by an hour or more between the mouth of the bay and the Minas Basin; use the station nearest your destination.
- Never walk out onto exposed flats without knowing when the turn is coming.
The best Fundy days combine both extremes: a morning on a sea floor that will be five storeys underwater by dinner, and an evening on a cliff watching the same water come back. The bay does this every day, without fail. All it asks of a visitor is to show up on time.