Gooseneck (sailing)

The gooseneck is the swivel connection on a sailboat by which the boom attaches to the mast. The boom may pivot in any direction, from side to side or up and down, by swiveling on the gooseneck.^[1]

Gooseneck swivel on jigger-mast of Nippon Maru sail training vessel in Yokohama harbor

The gooseneck may be a two-axis swivel as pictured. Having an integrated shackle for the tack is common. Goosenecks on older rigs may be formed by a loop attached to the end of the boom that fits loosely about the mast.

Gooseneck Swivel Connection On A Yacht