"André Gückel" wrote in message

does anyone have any experience with the above mentioned charter
company in Greece, maybe chartered a boat via their website? I
would be
interested in their opinions ...

André,

I suggest you contact:

http://www.sailingissues.com/greek.html

You'll see he has an email enquiry service which should cover your
needs.
--
JimB
http://www.jimbaerselman.f2s.com/
Describing some Greek and Spanish cruising areas