Jetty
A manmade structure projecting from the shore. May protect a harbor entrance or aid in preventing beach erosion.
Jib
A triangular sail attached to the headstay. A jib that extends aft of the mast is known as a genoa.
Jib netting
A rope net to catch the jib when it is lowered.
Jib sheet
A sheet used to control the position of the jib. The jib has two sheets, and at any time one is the working sheet and the other is the lazy sheet.
Jib stay
The stay that the jib is hoisted on. Usually the headstay.
Jib topsail
A small jib set high on the headstay of a double headsail rig.
Jibe
To change direction when sailing in such a manner that the stern of the boat passes through the eye of the wind and the boom changes sides. Careful control of the boom and mainsail are required when jibing to prevent a violent motion of the boom when it switches sides.