DICTIONARY OF

Jason Clause 185 Jib Iron
Jason Clause. Usually inserted in maritime contracts that are subject to Harter Act. As a
separate contract, it allows the owner of a technically 'unseaworthy' vessel to claim cargo's
contribution to General Average when he has exercised due diligence in making his ship
seaworthy in all respects, and the 'unseaworthiness' was such that it could not have been
avoided or discovered by any reasonable amount of forethought or care.
Jaunty. R.N. nickname for a master-at-arms. Corruption of 'gendarme'.
Jaw. Forked end of a gaff or boom. 2. Space between lugs of a shackle. 3. Distance along a
rope from any one strand to the next appearance of the same strand in a straight line along
the rope.
Jaw Rope. Rope by which jaw of a gaff is confined to mast. A parrel.
Jears, Jeers. Tackles at bunt of lower yard, and by which it is hoisted or lowered.
Jehazi. Undecked coastal dhow of about 20 to 40 tons. Usually has matting bulwarks.
Jergue. Old form of 'Jerque'.
Jerking Note. 'Jerquing Note.'
Jerque. Search of a vessel, by Customs authorities, for unentered goods.
Jerquing Note. Certificate given by Customs searcher when ship has been searched and no
unentered goods are on board.
Jet Foil. Hydrofoil propelled by water jets situated in the foils upon which the vessel rides
when at speed.
Jetsam. Goods that have been cast out of a ship and have sunk.
Jettison. Deliberate throwing overboard of goods or fittings for the preservation of a ship in
peril.
Jetty. Wharf, or other similar construction, that projects into the sea or harbour.
Jewel Block. Wood block, at yard arm, that takes a studdingsail halyard.
Jew's Harp Shackle. Special bow shackle that formerly connected cable to anchor.
Jib. Triangular fore and aft sail set on a forward stay.
Jib Boom. Boom projecting forward from bowsprit, on which it is housed.
Jib Downhaul. Rope by which a jib is hauled down and inboard along jib boom.
Jibe. 'Gybe.'
Jib Frame. Vertical frame at side of a marine reciprocating engine.
Jib Guys. Rope stays leading inboard and downward from end of jib boom.
Jib Halyard. Rope by which head of a jib sail is hoisted.
Jib Headed. Said of any sail resembling a jib in shape.
Jib Inhaul. Alternative name for 'Jib downhaul'.
Jib Iron. Iron hoop that travels along jib boom and carries tack of a jib (sail).