The following (and more) informations on how to get to the Campus of
San Servolo is at http://www.univiu.org/viu_howtogettoVIU.htm
Airport => San Zaccaria (=> San Servolo)
Alilaguna waterbus service http://www.alilaguna.com/ offers a service that goes from the Airport to Murano, the Lido, the Arsenale/San Zaccaria with a final stop at San Marco (so you can already enjoy a nice tour of the "laguna"). Tickets cost 11.00 euro and can be purchased in the arrival hall of the airport or directly on board. Boats leave hourly. Take shuttle bus from terminal to dock.
Train Station => San Zaccaria (=> San Servolo)
There are several choices from the train station to San Servolo. You must take a public boat - called "vaporetto" - either the n. 1, n. 51 or n. 82 boat, direction "Lido", and get off at the San Zaccaria boat stop. At San Zaccaria you must change to line n. 20. Both lines leave from in front of the Londra Palace Hotel.
San Zaccaria => San Servolo
The public boat from San Zaccaria to San Servolo http://www.univiu.org/viu_boats.htm leaves from the Riva degli Schiavoni between San Marco and the Arsenale. The stop is in front of the Londra Palace Hotel and you can take boats n. 20.
Note on Water and land Taxis: you can also take a private water taxi directly to your final destination which is an expensive choice. From the airport to San Servolo it costs about 75 euro or more! Take shuttle bus from terminal to dock. Alternatively you can take a land taxi to Piazzale Roma and from there catch a public boat as above.