We've now arrived in Montreal after a 2-day trip from Quebec City.
In an earlier post, I summarized how we planned our trip from Rimouski to Quebec. With very few adjustments, it all went as planned, and if anything, the currents actually were a bit more friendly than I was expecting.
When we were planning this trip, I did some internet searches around sailing up the St Lawrence. I didn't have much luck. I knew that currents were a big issue, and that they had to be taken into account in planning the trip, but I was hoping for more detailed information. I was able to find some information for going down river, but not much for making the trip in the reverse direction, against the prevailing current. Thanks to the couple that we ran into in Rimouski (as I mentioned in the earlier post), I was able to get much better information on planning the trip. I hope that my previous post, as well as the information below, are of use to anyone else planning this trip.
We decided to try do the trip from Quebec City to Montreal in two days, with a stop in Trois-Rivières. We had anchored in Quebec City, just a couple of miles downstream from the city on the south side of Isle d'Orleans. Quebec City has a very strong tidal influence, with tides of about 18 feet, so it is critical to time the currents properly.
On July 23, the tidal tables said that high tide in Quebec City was at 0927. According to the tidal tables, the current switches three hours before that, so we pulled up anchor at 0630. Coming through Quebec City was a blast, and we hit up to 11 knots under the bridge (our normal top speed is about 7 knots). We had two plans for the day. The first was to make it as far as Portneuf, about 30 miles away, which we thought we would reach by 1130. At that time, the currents are starting to change. We actually made it there shortly after 1030, so we continued on to Trois-Rivières. We were going against the current at the end of the day, but it wasn't too bad, and we reached here at around 1800. For the last hour of the day, we were going against about a 1 knot current.
At Trois-Rivières, we're almost out of the tidal area of the river. According to the current book, it is impossible to avoid adverse currents, but if you leave within the hour after low water, you can minimize the currents for the first little while. We timed our departure at 0600 the next morning, and caught some favourable currents for the first couple of hours. However, where Quebec City has an 18 foot tide, Trois-Rivières only has a foot or two, and the tidal currents are very weak. So, for almost all of the day until we hit Montreal, we were going against the currents, although they were almost always no more than about 1 knot, sometimes 2 knots. That let us cruise along at between 5.5 and 6 knots for the day.
Along the river after we passed Quebec City, we travelled in the shipping channel, dodging the occasional cargo ship. Just a few miles upstream of Sorel-Tracy, there is a secondary, pleasure craft channel. This runs for 18 miles before it merges again with the main channel, has lots of depth and clearance, has less downstream current, and is a much more pleasant trip. We then merged again with the main channel about 12 miles from our berth in Montreal, and remained in that channel the rest of the way. There is another length of pleasure craft channel for about three miles that we decided to pass on - there are lots of rocks if you stray out of the channel according to the chart.