Hi, I was in Makarska last September. There are three nudist beaches within walking distance from Town. The closest is Sv Petar which is on the peninsula that divides the town about in the middle. Its mainly rock platforms and gets a lot of use with people sharing tight spaces. The next closest is to the North. Keep walking along the promenade for about 1 km past the last restaurant. You'll know youre there when you see the porta potties on the inland side of the trail. This was more a series of small inlets and not much beach when the tide was up. The third beach was Nugal which is a longer walk to the south, about 30 minutes. But this was the most populated beach.
There are two nudist beaches in the Baska Voda/ Brela area and four beaches in the Igrane /Zivogosce area (that I know of). Not all are on the maps as official FKK. From Zigovosce you can walk to three naturist beaches. I understand Pisak has at least one...Its a beautiful area. Most of the popular beaches are reviewed on this website.