Which line controls jib luff tension?

• A. Backstay
• B. Jib halyard
• C. Jib leads
• D. Boom vang

Answer: (B)

Jib luff tension is set by the jib halyard. Pulling on the halyard tightens the leading edge of the jib against the forestay, smoothing wrinkles and shaping the sail’s draft along the luff. The backstay mainly affects mast bend and forestay tension (indirectly influencing luff tension), the jib leads adjust sheet angle and entry, and the boom vang controls the mainsail boom and its leech—not the jib luff. So the line that directly controls the jib luff tension is the jib halyard.