Daniel and Doug, The difference between a loose footed main and one with a bolt rope really is not a matter of turbulence at the boom. If the sail is captive in the boom the 'pressure' trying to escape will not be held in by the boom it will wander around across or under the boom. Slippery stuff that air. The better reasons for a loose footed sail are : The ability to build a 'roach' into the foot for additional (usually partially unmeasured) sail area. The lower third of the sail will maintain a smoother shape when adjusted by use of flattening reef or outhaul (sail doesn't bunch-up in boom track) The last reason is more important on a smaller boat due to scale, the lumpy foot area of the sail is a greater concern on a small sail. In the older days the loose foot was a small boat feature - today it is used by many larger boats - primarily for the second reason - nice clean edges and smooth transition and lower section of mainsail. I would ask the people at Baxter & Cicero Sails to see if my reason holds water or .... GO