There’s a good reason that cats employ wide, easily adjusted travelers. They’re the primary tool for trimming the main. On a catamaran sailing upwind, the mainsheet should be cinched home and the boom positioned just slightly leeward of centerline—just like on a monohull. But as you crack off, instead of first dropping the traveler and then easing the mainsheet, as you would on a mono, resist the urge to trip the mainsheet and only ease the traveler, always keeping an eye on those flowing telltales. Continue doing so even when bearing off to a beam reach and beyond. Only then should you begin to ease the mainsheet, and always in small increments. Remember: Watch those telltales.