Zurich Dockyard

Use SBB.ch/en
FROM is Zurich Flughafen and TO is Zürich Bürkliplatz (See)
That will show you the various routes. They all basically involve taking the train to Zurich and then walking to the tram and taking the tram down to the water.

You want to go to the ferry terminal, not the dockyard.

And its not a ferry terminal either...

There seems to be a difference of terminology here. In the US it does seem that usually boats leave from or berth at a dock. Whereas generally in Europe they leave from a quay, berth, pier or jetty.
In Europe a dock is an enclosed area of water where ships berth and a dockyard is where ships are repaired or built.

And on the swiss lakes, while the boats fulfil the functions of a ferry they are rarely actually called that IMMO. There may well be the odd exception to that general rule.

The first answer very neatly sidestepped such subtleties and just gave directions on where to catch the boats. And I think everyone here knew what you meant.

or you take the train to Zurich main station and walk to the lake