May i recommend the PRINCIPE:
You will find the hotel, if you click on the thris star from left on the bottom row of the card (near the Canal Grande). The hotel is just in front of the manin rail station and the vaporetto station S. Lucia. There is only one stop to Piazzale Roma, from wehere shuttle busses go to the cruise terminal.
Another (cheap) hotel is the IL MERCANTEDI VENEZIA. Lokk for it when going with your mouse cursor on the stars...
If have been in this hotels for some times.