Done this and had some hilarious experiences while trying XD
My first time was at a lake with a small island in the middle. At my first attempt i appeared to be a natural. After i managed to get the wind in my sail i sailed off, straight to the island, and since there are no brakes on the board i didn't know how to stop and it was a straight hit haha. Two friends came and rescued me, with one of them surfing my board back with me sitting at the end.
My 2nd attempt was at sea. And again .. got the wind in my sail and there i went .. wayyy to far off the coast and didn't manage to get back (lol) So there i was standing at my board waving, hoping someone would notice me and .. again i was rescued XD
My 3rd attempt was again at the lake with the island in the middle, and as usual, there i went. Suddenly it started to rain. Lightning and thunder broke loose and there i was at an open lake and again didn't know how to get back .. and again .. i was rescued XD lol
So i guess i'm a natural .. not so much in foil windsurfing but in getting rescued hahaha :)