Thanks all of you for the quick response, about the c4 and k4, sounds very good, i tried the software (bareboat pro) as mentioned by Paul, do you guys want to how it came out?, maybe you have some suggestions, let me know where to send it, sounds like a interesting proyect, resistance predictions were something close to 36 lb at 8 knots, whish i think is not bad compared with what i had before . I am trying to get the book, but keep posting ideas, as soon as i start i will make a web page to share with all of you. By the way, have any of you made any reasearch on surface resistance reduction?.
Tomas.