Navigating the Saint Lawrence Seaway

[hpeer]

Originally Posted by Chotu

This actually makes lots of sense.

Maybe it’s best done as a loop.

Even then, you have to buck the predominantly SW winds returning to the east coast usa

I’ve done this SW slog a couple of times. Once we had weeks of no wind, the other it was weeks of head winds. Not a whole lot of fun either time. But I was short on time, “delivery” of sorts as I was still working and could not play the weather.

[Mike OReilly]

Currents down the St. Lawrence come in two varieties; downstream currents and tidal currents. Leaving Lake Ontario, and down past Montreal you'll see standard downstream currents. We saw those measure from between 1 and 3 knots. Around Montreal the currents get stronger, I assume because of all the island channelling, and also the fact that the Ottawa River joins the St. Lawrence there.

Once past Trois-Rivières the tides and tidal currents really ramp up quickly. Travel really only becomes possible by running with the tides. Start off just as slack is taking hold, ride the wave downstream, and then be safely anchored before the flood tide has taken hold.

We flew past Quebec City, hitting current speeds of close to 10 knots, and anchored in tides around 15 feet. Here is a pic of our speed over water @ 5.1 knots and our speed over water at 11.2 kn. But we achieved just shy of 15 knots at one point, and at that point I didn't dare take my attention away from the tiller. I was fearful of losing control, and didn't want to contemplate what would happen to our full keel if we got broadside to the current.

These significant currents and tides persist down to about the Saguenay. Beyond that they remain significant.

[Mike OReilly]

Originally Posted by hpeer

I’ve done this SW slog a couple of times. Once we had weeks of no wind, the other it was weeks of head winds. Not a whole lot of fun either time. But I was short on time, “delivery” of sorts as I was still working and could not play the weather.

In contrast to the harder slog Howard had, we saw nothing but wind on the beam or aft. Most of the time it was great sailing. We travelled the river in July and August. The prevailing winds are westerlies through those months, but obviously it can be anything. Luck of the draw.

[Flagman101]

Originally Posted by Mike OReilly

Currents down the St. Lawrence come in two varieties; downstream currents and tidal currents. Leaving Lake Ontario, and down past Montreal you'll see standard downstream currents. We saw those measure from between 1 and 3 knots. Around Montreal the currents get stronger, I assume because of all the island channelling, and also the fact that the Ottawa River joins the St. Lawrence there.

Once past Trois-Rivières the tides and tidal currents really ramp up quickly. Travel really only becomes possible by running with the tides. Start off just as slack is taking hold, ride the wave downstream, and then be safely anchored before the flood tide has taken hold.

We flew past Quebec City, hitting current speeds of close to 10 knots, and anchored in tides around 15 feet. Here is a pic of our speed over water @ 5.1 knots and our speed over water at 11.2 kn. But we achieved just shy of 15 knots at one point, and at that point I didn't dare take my attention away from the tiller. I was fearful of losing control, and didn't want to contemplate what would happen to our full keel if we got broadside to the current.

These significant currents and tides persist down to about the Saguenay. Beyond that they remain significant.

I teach sailing in front of Quebec city.
The fastest current will be around 5 knots during spring tides.
Maybe 6 on some spots.
Your speed over water was probably 5 knots and yourspeed over ground about 11.2.not the other way around.
You can sail broadside to currents safely. I do it al tje time.
Part of the training is appraoching the marina with curret from the side.

[Mike OReilly]

Originally Posted by Flagman101

I teach sailing in front of Quebec city.
The fastest current will be around 5 knots during spring tides.
Maybe 6 on some spots.
Your speed over water was probably 5 knots and yourspeed over ground about 11.2.not the other way around.
You can sail broadside to currents safely. I do it al tje time.
Part of the training is appraoching the marina with curret from the side.

Sorry, what did I write? Yes, I meant speed over water and speed over ground. As I said, this shows 6 knots of current, and we achieved speed-over-ground of just shy of 15, so you do the math.

I'm happy to hear you think it's OK to go broadside in a full keel boat moving at twice its hull speed. That was not my impression, but I don't sail there, so thanks. Good to know.

[rslifkin]

Originally Posted by Mike OReilly

I'm happy to hear you think it's OK to go broadside in a full keel boat moving at twice its hull speed. That was not my impression, but I don't sail there, so thanks. Good to know.

Handling wise, it shouldn't be a problem, provided there's plenty of space around you to maneuver. If you're sideways and stopped relative to the water, you'd still be moving over ground at the speed of the current. But your ability to maneuver, etc. relative to the water should still be as normal, just with the current adjusting your speed and course over ground. Because of that, you may just need more space to make certain maneuvers (as you'll move over ground far more than normal despite normal movement through the water).

[Mike OReilly]

Originally Posted by rslifkin

Handling wise, it shouldn't be a problem, provided there's plenty of space around you to maneuver. If you're sideways and stopped relative to the water, you'd still be moving over ground at the speed of the current. But your ability to maneuver, etc. relative to the water should still be as normal, just with the current adjusting your speed and course over ground. Because of that, you may just need more space to make certain maneuvers (as you'll move over ground far more than normal despite normal movement through the water).

It wasn't the current per sey, it was the eddies that had me concerned. There were large whirlpool structures right beyond the bridges that I didn't like. You could really feel the rotational forces on the tiller.

My main experience with this kind of water is as a whitewater canoeist. That training taught me to be very careful around these things. I suspect our west coast cruisers would also have a lot to say, since they deal with them in the islands a lot more.

[Flagman101]

Mike, you are not going a twice your hull speed, your doing 5.1 knots. Your speed over ground might be faster but your are moving faster over ground.

[Mike OReilly]

Originally Posted by Flagman101

Mike, you are not going a twice your hull speed, your doing 5.1 knots. Your speed over ground might be faster but your are moving faster over ground.

Yes, I get it. Thanks.


Boat moving at 5.1 knots in the water. Boat moving at 14.8 knots over the ground. That tells me there is 9.7 knots of current. Or is this wrong?

[rslifkin]

Originally Posted by Mike OReilly

It wasn't the current per sey, it was the eddies that had me concerned. There were large whirlpool structures right beyond the bridges that I didn't like. You could really feel the rotational forces on the tiller.

My main experience with this kind of water is as a whitewater canoeist. That training taught me to be very careful around these things. I suspect our west coast cruisers would also have a lot to say, since they deal with them in the islands a lot more.

Bad spots in the flow like that are definitely a concern. It's not that you can't maneuver in them, it's a question of whether you can do enough maneuvering before getting thrown into a solid object.

[Mike OReilly]

Originally Posted by rslifkin

Bad spots in the flow like that are definitely a concern. It's not that you can't maneuver in them, it's a question of whether you can do enough maneuvering before getting thrown into a solid object.

Yes, and we were certainly clear of any obstacles. I'm not suggesting it's a major danger, but it certainly spooked me aw we flew past. The rotational forces felt very strong. I definitely did not want to play with them.

[Flagman101]

Never seen 9 knots of current there.
But yes near the bridges it gets weird with the eddies. But it's very local. Only about a 1/4 of a mile. Then it calms down

Yes it can be very intimidating to someone who has never been there.
Wind against current on this spot will be scary.
Also heb current is much stronger then the flow.
You can't go against it.

[Mike OReilly]

Originally Posted by Flagman101

Never seen 9 knots of current there.
But yes near the bridges it gets weird with the eddies. But it's very local. Only about a 1/4 of a mile. Then it calms down

Yes it can be very intimidating to someone who has never been there.
Wind against current on this spot will be scary.
Also heb current is much stronger then the flow.
You can't go against it.

It was indeed intimidating. You folks who sail out of QC have my admiration. It seems like tough waters to play in.

So true about the currents. We were going down, so followed the ebb. By the time the tide is well turned we had to be firmly anchored. There was no going against the flood (even if it was weaker).

Interesting to watch some of the locals use the tidal zones to dry out. I didn't have the guts to try, but I watched a bunch of boats anchor on a flat, and then hold a party while the tide was out. Their boats, including a few decent-sized sailboats, were high and dry.

[Flagman101]

You get used to it. But yes it's challenging. That is why I teach there.
I actually live in Montreal. I drive 3 hrs to the sailing school and teach for 10 straight days before coming back home.

I would never dry out in that zone
The bottom is full of debris and rock. Only tow spots with sand ans even there you get old steel cables and machinery from the days (way way back) of boat building
The stuff i pull up with anchor is unbelivable.
1 inch steel cables, a steel door from some king of furnase.

[Mike OReilly]

Well, some people do it. Here's a pic of a bunch of boats. It's not far south of Île d'Orléans close to Grosse Ille, so around 25nm downriver of QC. We're anchored about a mile away from the group, and the refraction distortion makes it hard to see, but I tell you, all these boats were high and dry, and the crews were milling around.

Some of the sailboats are quite large. As near as I could see they just put out an anchor, and let the tide ebb away. It was pretty facinacting to watch.

https://www.waterwayguide.com/explor...37&mode=marina

Lat: N 47° 03.617' Lon: W 070° 36.366'