You'll be fine. I wish if WDW was going to enforce a dress code they'd enforce it and not just blow hot air. We dressed for both the Yachtsman and Flying Fish/not fancy, but not our park clothes and it sort of took away having other folks come in in their junky tanks, halter tops, a set of kids in swim suits with wet hair. Heck, if we wanted that we could of gone to some counter service! We would of been more comfy in our park shorts and tops and tennies, but followed the rules that were given to us. Obviously WDW just gives lip service over this.