We've done Athens to Venice, which included Dubrovnik, Hvar, and Rovinj. We didn't have a chef walk, unfortunately. We did an overnight in Dubrovnik where we could have eaten in town. It is unlikely you will stay late enough to eat out in the evening unless it is an overnight. We did the Hvar Island discovery tour, which was good. They generally start around 9am. You will be tendering in. I don't recall swimming on that particular trip. Enjoy!