I have bought a 2nd hand 3 -years old Arerotech Air 6.4 sail., in mint condition. I didn't rig it nor try it out, yet because the lake is still solid frozen, , but it puzzles me that the specs on the Aerotech site indicate 180 cm as the boom length, But it is also the same distance between the mast and the clew end of the boom. They are flush, so that I cannot adjust the tension . It doesn't make sense. Can anybody comment on this .TKS Francone