In-boom furling

Unlike in-mast furling, in-boom systems can be retrofitted in place of conventional slab reefing. For an in-boom furling system to work efficiently, however, it has to overcome a number of problems.

First of all, the sail has to be led from the boom to the mast, but there needs to be space for the bearings for the central mandrel and the boom’s gooseneck fitting, so the whole sail has to move aft along the boom. To combat this, many in-boom systems have a protruding track on the trailing edge of the mast, while other units have the reefing mechanism at the aft end of the