Friends are going there, leaving Monday, in fact, and they aren't sure whether to take the vaporetto or a private water taxi. Emails have gotten no response. There are 6 of them with luggage--first time in Venice and I am not so sure all of them will be packing light enough to handle a longish walk.
No direct water entrance...and even with the taxi, they may be walking from the San Silvestro vaporetto stop where the vap would leave them (no bridges), or be surcharged for being brought "closer."
I would still encourage them to pack light (for Venice and airline reasons), and make sure they expect to walk in Venice in any case, with or without luggage!