Hi Bark, we went down the St. Lawrence a few years ago, including doing this section. We anchored all the way. The spots we used, which were all pretty good as I
recall, were:
• Beside Toussaint Island just above the first locks at Iriquois.
• Off Pointe aux Chats in the Salaberry de Valleyfield harbour.
• Off of Point Bell near the entrance to the
Canal de la Rive Sud.
The locks are fairly straightforward. Be sure to buy your tickets ahead of time online. Saves you
money, and most importantly allows you to avoid the little recreational docks.
The Canadian locks use ropes to secure
boats to the wall. They supply the ropes, but you probably want
work gloves to handle the lines. Some were pretty old and rough.
The US locks use a floating bollard. You supply your own lines to loop over the ballard. Easy.
They have schedules now, and I think you have to pre-register, but I'm sure you're on top of all that.