Nacra 500 MK2 Assembly Manual page 59

5.7.
Spinnaker external tack one line system
1.
Knot the tack line to the eyestrap on the underside of the bowsprit.
2.
lead the line through the double block.
3.
And back through the block on the forward end of the bowsprit.
4.
Tie the line temporarily to the bowsprit.
shockcord
59.