Venice, San Zaccaria area to train station

Is the departure by train, so you need to be at the station by 7:10, or by air, so you need to be at the airport at 5:15?

The vaporetti start early but it will take you about half-an-hour. Catch the 5.2 at the S. Zaccaria stop, direction Ple Roma. There is a departure at 6:24 am arriving at 6:51. This is the option with the least walking. Or play around with options here http://muoversi.venezia.it/en.

Oh, and quickest is a private water taxi ma costo molto!

Laurel, the muoversi app appears to use google directions and is quite confusing. There is no way to opt (that I can find) "least amount of walking", so it wants you to walk through town to Rialto and get a No 2 vaporetto there. It also contains a mysterious message,

Walking directions are in beta. Use caution – This route may be missing sidewalks or pedestrian paths.

Does that mean you are supposed to walk through canals?

Finally, if I put in the time of 6:00 am, it shows me routes for 1:00 pm. There is a 7 hour time distance between where I am and Venice. Is that the actual time in Venice, meaning I'd have to input 11:00 pm here to get the actual schedule in Venice at 6;00 am there?

Beta version indeed.

I prefer to go by the on-line timetable, although you need a map to go along with it. And there are three separate docks at San Zaccaria which are a bit of a walk from each other.

San Zacarria "D" No. 5.2 Boat: 6:06 arrive Ferrovia at 6:30, and the 6:26 arrive Ferrovia 6:50
San Zaccaria "B" No. 2 Boat: 6:13 arrive Ferrovia at 6:58
San Zaccaria "E" No. 1 Boat: 6:11 arrive Ferrovia at 6:51

So the 5.2 boat is the fastest from the "D" dock, which is in front of the Hotel Savoia & Jolanda.

Schedule boards should be posted at those docks to confirm the details Sam provided. Check it out in advance.

Forgot to add this, for those who love reading schedules.
http://actv.avmspa.it/en/content/orari-servizio-di-navigazione-0

Sam - We are here now and having no problem using the site on a laptop. I have not tried the app as all I do is check routes before we head out. When I did so with the OP's start and end points, it gave me three possibilities: 2 with significant walking and one using the 5.2 with negligible walking. As Laura says, though, best to go to the dock and check timetables the day before.

Laurel, I see you are in Europe now, so you don't see the weird time difference I get from where I am at on CDT. And I said app, but still thinking in the 20th century, I meant the online trip planner with a PC. I'm still not smart enough to use app's on my phone.

Sam - I have now seen some of the weirdness in the trip planner! I was given an option to walk to Murano and also to cross the Grand Canal at Ca'd'Oro on foot. And I could not force it to show me a #2 from Accademia to Ferrovia. Use with caution.