Many thanks to the charming chap (apologies, I've forgotten his name) who met at the Fondamente Nove Alilaguna stop and showed us to the apartment, which is only two minutes walk away.
I am sorry to say that our overall experience of the apartment was disappointing. This could be a lovely spacious apartment, but the owner needs to address some issues. Despite providing 3 coffee makers, there were no cups or bowls. It looked like people had bought their own plastic cups. I know it's Venice, but the drains need attention; at times the smell in the bathrooms and bedroom was unpleasant. The main bathroom is light and airy, but it's about time that the wooden slats in the shower were replaced.
On the plus side the apartment is well-located for the airport, set in a quiet street and there are local restaurants and a supermarket within easy walking distance.
I am sorry if these sound like minor niggles, but this is not a cheap apartment to rent, which raises expectations particularly with the basics.