Most people don't like to swim with big waves. So it is wise to ask someone local resident about the beach which hasn't big waves at that day. In the Greek island, the wind often change directions. So according the wind, any beach will has or will hasn't big waves.
Tourkomnima except of a beautiful beach, it has an incomparable advantage. You don't need to ask for the wind. This beach is divided by a narrow lane of land (see the above picture). So when one side of the beach has big waves, you can swim to the other side. Tourkomnima the two side beach.