Stays (nautical)

Stays are ropes, wires, or rods on sailing vessels that run fore-and-aft along the centerline from the masts to the hull, deck, bowsprit, or to other masts which serve to stabilize the masts.
A stay is part of the standing rigging and is used to support the weight of a mast. 
It is a large strong rope extending from the upper end of each mast and running down towards the deck of the vessel in a midships and direction. 
The shrouds serve a similar function but extend on each side of the mast and provide support in the athwartships direction. The object of both is to prevent the masts from falling down but the stays also prevent springing, when the ship is pitching deep. 
Thus stays are fore and aft. Those led aft towards the vessel's stern are backstays while those that lead forward towards the bow are forestays.
To "miss stays" is an unsuccessful attempt to tack.
Types of stays.
To stay. To tack, to bring the ship's head up to the wind for going about; hence to miss stays, is to fail in the attempt to go about.
In stays, or hove in stays, is the situation of a vessel when she is staying, or in the act of going about. A vessel in bad trim, or lubberly handled, is sure to be slack in stays, and refuses stays, when she has to wear.