Canada (Sask; all property is Provincial Jurisdiction, so will vary in all 13 provinces and territories) but ... inland waterways (lakes, rivers, ponds) are all public property as per Federal Law. Anyone can be anywhere on the water.
Private lakefront / waterfront property outside of a city, town or village, is public property up to the traditional water line ( 50 year high water line, 50 year flood allowance, etc) minimum +6.8 feet (2m) above that level or 60 feet (18m) from bank. The Permanent dock would be private property, however. Floating (non-permanent) docks, maybe not so much.
Any disturbance of shoreline or underwater habitat needs a permit to insure no fish habitat is harmed, so you can't just throw up docks anywhere you like, or at least you shouldn't because the cost will be pretty high if someone complains and you have no permit. Will involve at a minimum demolition of the dock, and returning the habitat and shoreline to it's original state. If you don't they will, and charge you about $2000/day to have their summer students do it for you.
If you can access the property via a road / driveway from a public road or highway, and the trespasser stays on that road / driveway, they are not trespassing until you instruct them to leave.
If you want to restrict access to everyone, you need a lockable gate across the roadway / driveway. Then everything behind the gate (and fence, if applicable) is private property subject to be posted (trespassing, hunting) every x number of feet (I forget the distance; it's a fair distance but think a few hundred feet and you'd be close enough).
You have to be careful that no easement exists if you want to restrict access to a waterbody surrounded by your private property. If there is a path to that body that people have used or do use, you won't be able to restrict access to the waterbody via that path or road. Once an 'easement" is established, it essentially becomes public access even if on private property, and they are very difficult to close. Best plan is to sneak it and hope no-one has the smarts to take you to court, because you will lose and now you've got a Court Order which will be a permanent note on the title. If no-one takes it to the courts, after a few years they won't be able to re-open a closed easement so you are good to go.