I imagine you can take the train, bus, maybe even water-taxi or a ferry?

Which is most convenient?

And what is most affordable?

And depending on the method of transportation, how much time should I budget for just getting to the airport?

Thanks!

We're going in May and found www.alilaguna.com for a 12E water taxi for San Marco to the airport. Anybody done this?

We took Aliguna from the Airport to San Marco. And it was lovely. It made a stop in Murano and took about 45 minutes and cost 12 euros. There's also a "gold line" a few times a day that is direct.

When we finished our cruise, we didn't have much time, so we took a land taxi to the airport. It was very quick and easy. I don't remember how much it cost, but it was reasonable.

We have taken the local bus from Piazzale Roma which is near to where the boats dock. If you have roller bags and don't mind walking, it's a fairly quick walk to Piazzale Roma. The bus takes takes less than 30 minutes to get to the airport and last year it cost 1E. It's ACTV's bus #5 and they seem to run very frequently - I'm quessing, but maybe every 10 to 15 minutes.

The fastest way is the bus. Direct nonstop way from the airport to the Piazzale Roma. From there you can get a taxi to the Stazione Marittima (about some minutes drive).
The loveliest way is by waterbus ALILAGUNA. But is a little bit more difficult to get from the Alilaguna-stop to the ship.
Click here for a map of the cruise port of Venice.

A map of Venice is here

Regards
Uwe

Cheapest is the bus Orage 1e no place for cases
Next cheapest is the bus (blue or green) 5e case storage under bus,which drops you at the Pizza Roma. When you buy the bus ticket you can also buy a vap pass at the same time but ask them not to stamp it. When you get to Pizza Roma you can store your extra bags for 3.50e a day and just take what you need for a couple days on vap. Just before you board vap validate ticket in machine as the time starts ticking from time you validate it.
3rd is the alilaguna is aroudn 15-16e
4th and most expensive but takes you to your door is the water taxi. Think $80-100.00

Thanks everyone for your help and advice!

I have found in my Venice travels that the aliguna, buses, and vaporettos are cheaper, BUT, for absolute peace of mind, I would recommend the more expensive water taxi. No extra luggage fee. You are the only ones on the boat besides the driver (a rare luxury in Italy). And, if prearranged before boarding, they can often take you directly to your destination with minimal walking. They also picked me up from my hotel and delivered me to my cruise ship for 60euro. That was a total price for 4 people. You never even have to touch your luggage. There were Royal Caribbean staff at the taxi stand that handled everything.
Very simple and very relaxing.