World’s Highest Tides Ecozone

The World’s Highest Tides Ecozone presents an extraordinary tidal landscape. This includes the upper basins of the Bay of Fundy, where the peak tidal range is around 15 m (50 ft) — five times higher than typical tides on the rest of the Atlantic coast! The world’s highest tides can be experienced as three different phenomena: tidal bores and rapids, horizontal tid al effects, and vertical tidal effects.

Cyclists at Medford, NS.

Where To See the Greatest Vertical Tidal Effect

The tidal range is normally measured as a vertical distance: the change in the ocean’s elevation from high tide to low tide. In the World’s Highest Tides Ecozone, the tide’s vertical change can be 15 m (50 ft) or more. The best way to see vertical tides is to visit small harbours around the Bay that empty at low tide and then completely fill about six hours later at high tide. Fishing boats that bob in the water alongside wharves at high tide sit on the ground below at low tide. Wharves along the Fundy coast in Nova Scotia (Halls Harbour, Parrsboro, and Advocate) and New Brunswick (Alma and St. Martins) are good locations for viewing extreme vertical tides. At Hopewell Cape, NB, visitors at low tide can walk on the ocean floor among the incredible rock formations that the tides have carved. As the tide comes in, visitors can see these formations become small islands. The best way to see the tide’s vertical change is to visit a site at high tide and then return to the same site six hours later at low tide.

Low tide, Five Islands Provincial Park, NS

Low tide, Hopewell Cape, NB

Hall’s Harbour, NS low tide, high tide
Hall’s Harbour, NS low tide

Where To See the Greatest Horizontal Tidal Effect

The tidal range can also be observed as a horizontal change. In some parts of the Bay, the tide retreats as much as five km (three mi.) at low tide, leaving vast areas of the ocean floor exposed. In Chignecto Bay and the Minas Basin, a fascinating inter-tidal zone of beaches, rock ledges, and sand flats is exposed at low tide. At low tide, visitors are able to walk on the ocean floor. The ocean floor is accessible at low tide through local parks and beaches in communities all around the Bay of Fundy’s coast. However, visitors who venture onto the inter-tidal zone in Chignecto Bay and the Minas Basin at low tide must be very cautious, as the tide can move extremely fast when it turns and starts to come in again. At Evangeline Beach (NS), Dorchester Cape (NB), and Mary’s Point (NB), huge flocks of up to 100,000 migratory shorebirds converge to feast on the inter-tidal zone’s fertile mud and sand flats. Each summer, this area exposed at low tide becomes a critical feeding area for birds on their inter-continental migratory flight. Care must be taken not to disturb migratory birds during their feeding period.

Low tide, Five Islands, NS

Exploring sea caves at St. Martins, NB

How to See the Tides

In the World’s Highest Tides Ecozone, visitors can see two high and two low tides each 24-hour period. The time between a high tide and a low tide is, on average, six hours and 13 minutes. As such, you can reasonably expect to see at least one high and one low tide during daylight hours. High and low tide times move ahead approximately one hour each day, and tide times vary slightly for different locations around the Bay. Check with the community you are planning to visit for accurate high and low tide times.

Low tide, Hopewell Cape, NB

Where To See Tidal Bores and Rapids

The Bay of Fundy’s tides also cause tidal bores, rapids, and whirlpools. Tidal bores can be viewed from shore in the Hantsport and Maitland areas of Nova Scotia or, even better, can be experienced in the water during a zodiac boat ride on the nearby Shubenacadie River. Here, visitors can ride on the Bay’s largest tidal bore when the incoming tide meets the resistance of the river’s exposed sandbars, creating three-metre-high waves and wild rapids. Visitors can also take a thrilling jet-boat ride through Reversing Falls in Saint John (NB) where the incoming tide reverses the river’s natural flow and creates extreme tidal rapids. Cape d’Or (NS) and Cape Enrage (NB) are great locations for seeing tidal rapids from shore. Intense tidal whirlpools also occur around the coasts of Deer Island and Campobello Island in New Brunswick.

Tidal bore rafting, Shubenacadie River, NS

Tidal rips, Grand Manan Island, NB

Tidal rips, Cape d’Or, NS

Jet boat thrill ride, Reversing Falls, Saint John, NB

The Science of the Tides

Tides are the periodic rise and fall of the sea caused by the gravitational pull of the moon and the sun on the Earth. Fundy’s tides are the highest in the world because of an unusual combination of factors: resonance and the shape of the bay. The water in the Bay of Fundy has a natural resonance or rocking motion called seiche. You could compare this to the movement of water in a bathtub. Although the water in a bathtub sloshes from one end to the other and back again in a few seconds, it takes about 13 hours for the water in the bay to rock from the mouth of the bay to the head of the bay and back again. As the ocean tide rises and floods into the bay every 12 hours and 25 minutes, it reinforces the rocking motion. To imagine this, picture an adult giving a gentle push to a child on a swing. Just a very small push is required to keep the swing moving. Likewise the seiche in the bay is sustained by the natural resonance of the ocean tides. The bay’s shape and bottom topography are secondary factors contributing to Fundy’s high tides. The bay becomes narrower and shallower [from 130 m (426 ft) to 40 metres (131 ft)] toward the upper bay, forcing the water higher up onto the shores.

Source: “Tides of Fundy” by the Fundy Guild at Fundy National Park