Top (Topper) is a reaching headsail with the foot cut very high, used when the boat is heeled over a little, but not pointing as high as it can into the wind
, and powering through waves.
They have the same LP measurement as the No. 1 genoas, but is high-clewed and fuller in shape, so the power in the sail is carried higher and further aft.
Jib Tops are great sails
to use in the range of about 55 to 75 degrees of apparent wind
, but are actually less effective than the genoa
in breeze less than about 10 to 12 knots.
At higher wind speeds, they can be carried effectively at broader angles until the spinnaker
becomes the faster sail.