Lake Balaton. There is a few kms long sand bank parallel to the southern shore. Between the shore and the bank, you will find flat water, while outside the bank, there is deep water and quite choppy. You should be careful, certain areas have very shallow water and water tends to be less and less from year to year. Behind the sandy part there are rocks and a concrete breakwater. Outside the beach area, there are fishing platforms, so be careful with those.
The beach of Balatonfenyves is about 1km long. As you come out of the water it is as follows: they have created a sandy beach (about 40ms wide), that reaches about 500m long and is perfect for landing the kite or starting from. Then there is grass (mostly taken by sunbathers) and the walkway.
Season is 7 months long, from April until October. Off season is cold and the lake is frozen. In spring months you will need wetsuit, also during autumn. Summer months are hot, but you might need a shorty in case of strong northern winds. Water: During spring: 10-17°C. During summer 20-27°C. During Autumn 18°C to freezing.
Winds are not regular. Sometimes weeks without wind, sometimes every third day. Winds usually come with fronts and can be gusty. Northerly winds are the favorite 3-7 Bft depending on the strength of the front. Southern winds can only be used on the northern shore. They bring real hot air temperatures, but are mostly extreme gusty. Eastern winds tend to be very steady but not stronger than 4 Bft, and you can catch it in the morning hours.