It's about a 15 minute walk to the Piazalle Roma (sp?) You can probably find some little markets over that way but you would have to get away from the Grand Canal. Or you can grab the vaparetto there down the the Rialto Market (NE of the bridge) but it will take you some time. A lot of little delis would have some food items.
A Bad Day At Sea [with power] Always Beats A Good Day At Work
Alaska 2014 - haven't picked a cruise yet
Carnival: Glory 2004, Destiny 2008, Splendor 2009, Freedom 2011, Valor 2012
Celebrity: Summit 2011
Princess: Ruby 2010, Caribbean 2013