That would be fun. I usually launch from the Thompson park right next to Sarasota sailing squadron which is on the south end of longboat. It's a nice central location where you can go south or north. I tend to stay close to launch (and shore) in the winter, and don't like to venture into the gulf in the winter ( I try to stay in Sarasota bay, and only go out when other boats are around). It's about 13 miles from City island up to Anna Maria I've sailed up there many times in the summer, it usually takes me a couple hrs to get there when the winds are right. I've sailed up to Ft Desoto and Egmont key a few times to go scuba diving, but found it is much easier to launch from Ft Desoto to get to Egmont key it's only about 6 miles out to Egmont but there is not much to do out there besides snorkel (we meet our powerboating friends there and anchor just off shore (can't go on the land)). When we can get in there it's fun for us to camp at Ft Desoto park but it's usually full.
I haven't been there before but it looks like there is a city beach on south bay blvd (near pine st (city pier)) on Anna Maria that we could probably launch from. I car top my TI so I can launch from anywhere there is parking near the water (a really nice feature of the Adventure boats).
I don't know that area very well, so if you find a better place, PM me some weekend after xmas and we can go out (weather permitting). I'm working on my boat right now so it won't likely be done till after Xmas (making all new sails).