 This can make the boat much more vulnerable in storms when a partly furled foresail has exactly the wrong effect on boat position relative to wind and waves while hove-to and this, though less of an issue for racing, is still an issue for long-distance cruising.The performance of the sail is dependent on having a forestay which is taut.If the forestay is allowed to slack, the sail will lose its airfoil shape and not perform as well.