Vassilliki Bay is a natural wind phenomenon. The weather forecasting model will not capture the specific geology of the bay. There is a daily wind shift created by a katabatic wind dropping of the speed slopes of the headland.
This effect drags wind over the headland, pulling and amplifying what pressure there is on the Ionian side.
You can expect this effect to last from 1400 to 1800. There are visible tells in the cloud formations as they stuck up moisture from the olive groves and get fed over the headland. As they start to move, the cross wind builds.
This dependable wind is why Vassilliki is a sailing and windsurfing mecca.
Top windsurfer local, Nicko, has clocked 38 knots. Top Catamaran sailors from all over the world train in this bay.