There are 3 types of cable lifts. The overhead cable lift, dockside cable lift and the free standing cable lift.
It is Muskoka BoatlIfts opinion that the overhead cable lift is the best valued lift. Its versatality and cost make it hard to beat. Typically the overhead lift will be installed in a boathouse or boatport. It needs the building structure to hold the boat weight. The typical overhead cable lift mounted in a boathouse is in the $6500 area (installed).
The dockside cable boat lift for small boats and jet skis can be found in the jet ski tab. Muskoka Boatlifts does not sell a dockside cable lift for large boats. We would refer you to Viking Boatlifts in Oakville www.vikingboatlift.com/photos.html. It is our understanding that you would be in the $9000 plus range for this kind of lift (20ft boat ).. You need to contact Viking for pricing. Deep water and winter boat storage can be accomodated by this lift.
Free standing cable lifts have an aluminium structure in the water to lift the boat. They typically need to be removed from the water for the winter which can make them burdensome. They are available with a manual or electric winch The price range is broad. A lift that can handle a 20ft boat with an electric winch would be $7900 installed while a manual winch fixed leg lift would be $4400 (17ft boat). Water depth 12" to 66".