2 – staysail 3 – spinnaker 4 – hull
5 – keel 6 – rudder 7 – skeg 8 – mast
9 – spreader 10 – shroud 11 – sheet
12 – boom 13 - mast 14 – spinnaker pole
15 – backstay 16 – forestay
17 – boom vang A backstay is a piece of standing rigging on a sailing vessel that runs from the mast to either its transom or rear quarter, counteracting the forestay and jib. It is an important sail trim control and has a direct effect on the shape of the mainsail and the headsail. Backstays are generally adjusted by block and tackle, hydraulic adjusters, or lines leading to winches.[1]