hey thanks you have help me a lot with this sail Calculator
but when that's right i schould take a 3,22 sail for 25 knotes and in my opinion it's a littel bit to small . And I have just 3,5 but that's an old one and a 4,7 sail from 2008
but I'm looking forward to this trip altough it will be have hard conditions. . thanks for your answers.