Extract from the 1985 HiFly brochure

The rope is a a safety leash but is not strictly speaking needed. It is not mentioned in the brochure but if you want it get some shock cord and run from bow attachment point to universal base above the rubber joint. Occasionally the uni would pop out of the track or fixing point or break so this preserves the rig and stops it separating from the board. Can be a good thing if it happens offshore or in a big waterway. Beware of the shock cord, because it can hurt you when the rig pops out !