100% agree with Symphony on this, both in regard to Kemp Sails (made my current main sail), and in regard to calling in someone local. Having said that, Kemp Sails are not local to me in North Wales, but they would be for jase71. However, as Symphony mentioned, they put a lot of information up on their web site such that I did the measurements for the main sail myself but using their guidance, and they confirmed from their records that my measurements matched those they had on record for a 2002 Bavaria 36. They made the sail, it fitted perfectly, and has been in use for the last three or four years.