J   Juliet

I am going to send a message by semaphore

 
Jack

n   The flag flown on the jackstaff at the stem of a ship.   British Royal Navy ships fly the Union Jack:  the same flag flown elsewhere (on land) is the Union Flag.

A commercial vessel might fly a Pilot Jack (a Union Flag with a white border) to indicate that she carries a pilot.

n   A sailor.   Also Jack Tar.

 
 
 
 
Jackstaff

The flagstaff at the stem of a ship on which the jack is flown.

 
Jackline
A wire rope or (preferably) a webbing strap stretched taut between the cockpit and the stemhead,  on both sides of the boat,  to which a crewman might clip a harness tether when moving or working forward.
 
 
Jackstay

A rope, bar or batten placed along a ship's yard to which the head of a sail may be bent.

Modern square rigged ships have jackstays,  to which harness tethers can be clipped,  along the yards.

 
 
Jacobs ladder

A rope or chain ladder that can be lowered over the side to assist boarding.

On square-rigged ships,  a ladder from the shrouds to the top to help those who would prefer not to use the futtock shrouds.

 
 
Jam cleat

A form of cleat which holds a line without a knot or a hitch,  but simply by being jammed between two parts.

A cam cleat has spring-loaded asymmetric rollers,  or cams.

 
 
Jetsam

Jetsam is part of a ship, its equipment, or its cargo that is deliberately cast overboard or jettisoned to lighten the load in time of distress and that sinks or is washed ashore.

 
 
Jettison

To throw cargo and gear overboard in order to lighten a vessel in danger of foundering.

 
 
Jetty

A stone or earth embankment protruding from the shore into the sea to provide calm waters in its lee,  and at which vessels might load and unload passengers and cargo.

New Quay,  in Wales,  has a jetty to protect its tiny drying harbour from S'Westerly winds.

The floating pontoon at Ha'penny Pier,  Harwich,  is a jetty for mooring small craft.

 
 
 
Jib boom

A spar used to extend the bowsprit.

 
Jib

The foremost fore-and-aft sail on a boat.   A jib is often set as a staysail from the forestay:  if not,  it is set on its own ha’lyard and luff-wire as a flying jib,  often from the end of the bowsprit to the top of the mast.

 
 
Joggle

A notch cut into the frame or rib of a clinker-built boat to accept the land of the planking.

 
 
Jolly boat

A ship's small boat, launched from the deck.

 
 
JRA

Junk Rig Association

 
 
Junction buoy

The IALA-B version of a preferred channel marker.    A red and green horizontally striped buoy used in the United States to mark the separation of a channel into two channels (when returning to harbour).   The preferred channel is indicated by the colour of the uppermost stripe.   Red on top indicates that the preferred channel is to the left as you return, green indicates to the right.

 
 
Junk

n   A slang word for things which tend to accumulate,  especially in a workplace,  and are unlikely to be of any further use or value.

n   A typically Chinese sail or sailing vessel.

The sail itself is a battened balanced lugsail,  originally of bamboo and woven bamboo fibres.   The JRA has carried out extensive research on junk-rigs.

The vessel has a characteristic shape,  with fore- and stern-castles,  internal water-tight bulkheads and a large perforated rudder which can be unshipped.

 
 
Jury rig

A temporary,  often makeshift,  arrangement of spars and sails.

Repairs after the rig has been damaged.

When Hornblower's friend,  Lieutenant Bush,  lost part of his leg in a battle he referred to his wooden prosthetic leg as a "jury leg".

John Starkie

March 2018

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