I agree with JacaRanda that it is most likely a Snowy Egret, but in your part of the world is more likely to be a Little Egret, as they are "cousins" - just different parts of the world. Cattle Egrets have a yellowish bill that can be a bit reddish in Spring and their feet are usually black unless in breeding plumage.
The image does look a little fuzzy to me. That could result from "sizing" it for the web, or it could be a bit of a focus problem. One thing to remember for birds, in flight or not, is to make sure that the eye is in focus.