I put a Mystere 6.0 rig on my Hobie 18 and it fit perfectly. All I had to change was to add a new boom bale about a foot forward of the existing one on the Mystere boom (the rigging fit like it was made for the Hobie). Then I added a 170 sq. ft. roller furling screecher. It was absolutely unbeatable in light air. One capsize and it took an astounding effort to right the boat even though the mast was only two feet longer (probably because of the furled screecher more than the extra 2 feet of mast). A much more succesful iteration was just using a cutdown Mystere 6.0 pinhead mainsail to make a "Mystobie" flat head sail. Lost only 2 or 3 sq. ft. of sail area off the top and got a fuller mylar main with LOTS more roach. It beat Hobie Miracles boat for boat pretty easily. It had a wide wind range and won every race I entered even with multiple rating hits for bigger mainsail and flat head main. (I even made a new "Mystobie" logo for it by combining the Mystere and Hobie logos) It just proved to me how fast the Hobie 18 COULD be and how easily the classs could have been saved if there had been a dedicated class association. It also proves that every now and then a "Frankenboat" can be a great success. It is hard to own several different boats and not want to see what could be...