This little beach just below the Cave of the Nymphs is a wonderful quiet place for a swimm. It's got a Blue Flag of the EC, a food stall, and clear waters. Here is where the Phaeacians disembarked and laid the sleeping Odysseus on the sand.
At the left side of the main harbour, towards Dexa Bay, there is a small pier (where the big ferries leave) where many yachts park when they are in Vathy. I used to wander around in lazy nights after dinner to see the big boats...