Under Sail:  Furlboom uses a conventionally cut mainsail and allows for belly, roach, and luff curve.  If you want an no compromise mainsail with  sail shape and performance and ease of operation Furlboom is for you.  The Furlboom was designed by sailmakers and  built around the mainsail rater than the other way around.  

There is no comparison to a Furlboom sail and in mast sail. And Furlboom has the best sail shape in the in-boom industry.