Gondola Boat yard tour

I don't believe they do tours of the gondola boatyard, as it is very small.

A gondola boat yard - where they are built and repaired - is called a Squero.

There is a very visible one in Dorsoduro just the Rio San Trovaso across from my favourite cicchetti bar, Cantinone già Schiavi http://www.timeout.com/venice/restaurants-cafes/venue/1%3A22729/cantinone-gia-schiavi

It is known as the squero di San Trovaso. They have a web page, all in Italian at http://www.squerosantrovaso.com/ If you click on "Visite" you can see that they run half hour visits for groups only. Perhaps you can hook up with an existing group.

Then again is you take a bit of time at the Cantina having your Ombra you may not want to cross the rio.

Everything is pretty much out in the open, like the photo on their website, and on Rick's video visit, so from across the Rio you can easily see the boats out, the open sheds, the flower baskets, and get some super photos.

It is adjacent to Chiuso San Trovaso.

Vaporetto Zattere or Accademia.

.... no, I've never been on the visit. I see all I need to from across the rio.