Hi Fodorites.
we are arriving to Venice with the cruise ship and are going to stay one extra night after the cruise is over. It's our second time in Venice, we spend there 3 days when we were there 4 years ago (I don't count another time 20 years ago).
Ideally, we would like to stay not far from Piazza San Marco but I am concerned that it may not be convinient to get to the airport, our flight is at 11 AM next day.
What would be a good central location that is also convinient for the airport? I have points at Westin and may use them for stay. Is it a good option for one night?

I've been several times here or there until I found hotel Flora close to San Marco. I left it last time to go to the airport and had no problem - I ahd to take a vaporetto - what a way to start a trip...
11 AM is no prob - plenty of time to reach it on time.

Are you willing to pay for a private boat from your hotel to the airport, yes or no?

Why ? No more public boats ? There were last I was there.

Is there a particular reason for staying close to San Marco? For only one night, I would just stay close to the train station. Faster to get off the cruise and get to the hotel, drop off luggage and be out exploring. Hop on a vaporetto to see San Marco, no luggage to deal with. Next morning, either leave luggage at the hotel for another hour or so of walking, or stash it at the station. Pick it up and catch the bus from Piazzale Roma to the airport.

The Alilaguna departs from San Marco to the airport regularly. It's a nice trip and takes about an hour. You can pre-pay tickets online.

This is a lovely hotel, short walk from San Marco but along a tiny alley with its own little garden.

http://www.hoteldopozzi.it/

http://www.alilaguna.it/en

Blueeyedcod, that little hotel looks fabulous! Glad you posted it for the OP. I will keep it in mind for our next trip.

Thank you Blueeyedcod for posting those links. I have a hotel reserved close to this hotel and am debating the best way to and from the airport to the hotel. This may work perfectly.

I strongly prefer Locanda Orseolo if it has openings.

Over closer to the train station/Cannaregio is Domus Orsoni, in good location for last night before departure, IMO.

What: >>Why ? No more public boats ? There were last I was there.<<

Because if the OP is willing to pay for a private boat, that opens up the options of places to stay and defines what's "convenient."

How much would be a private boat from let's Westin hotel? I can get a room at Westin using the points. My understanding is that we can take alilaguna to the airport though it will take about hour and a half to the airport.

It's about 100-110 euros for a private boat. Only you can decide if that's worth the money, but it's a far nicer, and quicker, experience than the Alilaguna, which is a slow, utilitarian way to get from Point A to Point B. (Not criticizing it or the choice to use it; just saying what it is.)

I assume you're talking about the Westin on the Grand Canal. If so, then the boat probably would pick you up right at the hotel, adding to the convenience.

One other option you could look into, sort of in between the Alilaguna and a private boat, is booking seats on a private boat that picks up other passengers. That would end up costing you something like 30-35 euros pp. You can book that online at websites like Viator or through your hotel.