Before the development of furling jibs, the jib had to be hanked onto the forestay with a series of shackles running the length of the sail’s luff. While hanked-on jibs are still used on many racing boats, on which sail changes are common, furling jibs are used on most cruising boats, especially midsize and larger boats.
At the base of the furling unit is the furling drum. Above it (hidden under the sail in this photo) is the furling foil, a flexible grooved structure that surrounds the forestay from the drum to a swivel at the top of the stay. The jib is hoisted with its leading edge in the groove of the foil—typically only once at the beginning of the sailing season. Then the furling line is pulled out of the drum, causing the drum and foil to rotate and the jib to roll up around the foil.
With a furling jib there is no need lower the jib and remove the sail hanks after each sail. A furled jib always remains raised and ready for use.
Remember to monitor changes in the wind so that you can furl in the jib early when it's easy rather than late when it's difficult or dangerous. You can learn to read the wind or use an inexpensive handheld wind meter.
The following pages explain the furling and jib reefing process.