The day before yesterday, we experienced a tornado warning, torrential rains, and strong wind and waves. But yesterday, it was 70º F (20º C) and sunny, and the river was as smooth as glass. With the tide and the current in our favor, we motored from Portneuf to Quebec City at an average speed over ground of 9 knots (with peaks of 12!) and reached Québec City in record time. Although, we didn’t sail, the trip was magnificent, especially at the end when Le Chateau Frontenac came into view. Très beau!
At the beautiful Marina Port de Quebec, we met up with one of the key members of the Women Who Sail the Great Lakes, Julie Thorndycraft. Julie, along with seven other amazing women, have been invaluable in providing us important information and tips and tricks such as lock, tide and current information, suggested passages, anchorages and marinas to take advantage of, and those to avoid.
The rest of the day we spent walking around Québec City with our friends, Cheri and Jon. It was so much fun! We felt like kids out of school for the summer with nothing to do but walk the streets. We plan to be here a couple of days touring the city, eating in as many restaurants as possible and doing as little laundry and provisioning as possible, before heading into the more natural parts of Canada.
Sailing with Tides
As lake sailors, tides are usually not a factor, so it’s been fascinating to discover them and learn how to use them to our advantage and avoid their dangers.
At Quebec City, the water level changes more than 11 feet (3.5 meters). When the tide flows in from the Atlantic (“flow”) it creates an upstream current and when the tide flows out to sea (“ebb”), it creates a downstream current. However, the timing, strength (“set”) and direction (“drift”) of the current is not synchronized with the tide itself. The natural seaward direction of the river current combines with the tidal current. This combination leads to longer and stronger ebb tides than flow tides. This adds up to a very complex analysis that is documented in a 130 page almanac by the Canadian Hydrographic Service.
For now we’re keeping it simple by departing around high tide and riding the ebb tide current. For example, yesterday, we left Portneuf at high tide. Although the boat was traveling at 6 knots relative to the water, we were actually traveling 12 knots at times relative to the earth.
In this region, the tides are semi-diurnal. Since tides are caused by the gravitational pull of the moon, and the moon takes about 24 hours and 50 minutes to orbit the earth, a full tidal cycle is about 12 hours and 25 minutes.
In order to keep the water level constant in the Marina Port de Quebec, it has its own lock that raises or lowers boats from the river level to the marina level!
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