I have a catalina 25 that I've owned for 2 years now and the main sail doesn't seem to be right. This sail is I think about 15 years old and seems to be in good shape. I have only had one other boat which was a 19 Oday and its main was not like this.The aft end of the sail seems to be to loose. If I pull down on the aft end of the boom it will correct it. Its like the aft end of the sail has stretched, if that is possible. Thanks for any advise.