As a single-letter signal it means, ‘I am on fIre and have dangerous cargo on board; keep well clear of me’. In the Morse code it is .– and in the phonetic alphabet it is Juliet.


The Union Flag or Union Jack is the national flag of the United Kingdom, but it is worn at sea only by ships of the Royal Navy, or ships with royalty aboard. (Please see Ensign.)


A pole with a cylindrical cage on top, forming a beacon. There never seems to be anyone, or any thing, in the basket. Odd …


The staff right forward on a warship where the Union Jack is flown. Pleasure craft fly an Ensign, and thus may have an ensign staff, and it will be shipped right aft.


A tightly stretched wire to hold the edge of an awning or a sail, or along which something may slide. If the Coastguard ever rescue you by breeches buoy they will haul you along a tautjackstay. But the most immediate use of ajackstay for the average boat-owner is when stretched along the deck as a lifeline for his personal harness.


A short yard which is bent to the foot of a topsail to carry it aft of the gaff.

Jaws (1)

The fork of a gaff which seats around the mast.


Goods thrown overboard, originally to lighten a vessel, but also
applicable to wantonly abandoned rubbish – which is illegal. (And see Flotsam.)


Properly the foremost sail, and the one set to the bowsprit end. Aft of the jib there would have been a forestaysail (Staysail for short) hanked on to the forestay. Some people still call any such sail a staysail, and all credit to them, but since on many modern boats the staysail is the only Headsail, it is commonly called the jib’ by the great army of people who find it hard to cope with words of more than one syllable.

Jib topsail

A small jib set flying above the ordinary jib.


A bowsprit upon a bowsprit, so to speak. A spar which can be extended forward of the bowsprit to carry an outer jib in light weather.


In the days when gaff rig was common any sail without a spar at the top -like a jib, with three sides instead of four – was called ‘jib-headed’. The term is rare now, but those who read the older books will come across it. Also see Marconi.


A light spar which is used to hold a jib or staysail outboard when running with the wind free.


Just the simplified, American spelling of Gybe

Jiffy reef

A popular and efficient type of Slab reef. The reefing-line is fixed to the main boom at a predetermined point (either tied around the boom through a slot in the foot of the mainsail, or to a sliding eye in a track under the boom, both near the clew) and thence up through the reefing eye on the leech,then back down and through a turning block on the boom and forward to the mast. It can then be secured either by a lever cleat within the boom or to a cleat on the mast, or via turning blocks back to a cleat on the coachroof. The last method gives total control from the cockpit. The slack sailcloth can be reefed conventionally or if racing, and on a short windward leg, tidied only at the mast end so as not to create exces¬sive drag.This is the most efficient system of mainsail reefing in that it flattens the sail for stronger winds.


The small mast (and also the sail) which is carried right aft in American yawls. On both sides of the Atlantic, Mizzen is the more modern term of both mast and sail, and especially the sail. Where differentiation is needed, one says Mizzen¬mast, but never ‘mizzen sail’.

Jill about

To move around idly with no set course

According to Richard Mayne’s book The Language of Sailing, to jill about was first noted in a nautical context in a 1955 issue of The Times and may derive from ‘gill’, a measure of alcohol, when ‘gilling’ was an 18th century term for pre-prandial wine drinking, later taking ones drinks in different places.

Jockey pole

Please see Reaching Strut


The Junior Offshore Group provides highly competitive races for IRC rated yachts with a full programme grouped into an Offshore and an Inshore Series, both running throughout the season.

Started in 1950, JOG is run by its members with a professional secretariat. It does not have a permanent club house but uses drinks receptions in the host port at the end of most races to create a focal point for club members to meet regularly. At the end of each race a particular point is made to seek out new members to welcome them to JOG and to introduce them to Committee Members and co-members.

JOG races in three classes, but with a focus on ‘smaller’ boats with a current upper TCC limit of 1.200 (equivalent to the top end of RORC Class 0, Division B) and no lower limit provided a yacht complies with the relevant ISAF Category (inshore: Cat 4; offshore: Cat 3). The class limits are adjusted from time to time to reflect the changing patterns of boat ownership. For 2009, the classes are: Class 3: 1.036 to 1.200; Class 4: 0.976 to 1.035: Class 5: 0.975 and below (for historical reasons, there is no Class 1 or 2). Advertising or sponsorship of individual boats is not permitted (IRC Rule Part 4: 31.1).

Prizes are awarded for each class in each race and for each series as a whole.


A large staysail, usually associated with a cutter. Long in the foot, it is set to the hounds, and is thus lower than the typical Genoa of conventional Bermudan-rigged yachts.

Jumper stay

A stay on the fore-side of a mast, to prevent it from bowing forward. It is taken over a jumper strut, the strut providing the rearward push at the desired point, commonly where a forestay meets the mast about three-quarters of the way up.

Junk and junk rig

Junks are the native craft of China and they take many forms, with up to as many as five masts with a variety of features which could fill a book in themselves. It is the rig which has attracted many Europeans for its effectiveness, cheapness and ease of handling and reefing. In brief the junk rig sets a Lugsail on an unstayed mast, as shown in the sketch. The sail is made up of many panels, with full-chord bamboo battens between. Each batten acts effec¬tivelyas a boom, and each has its own sheet, with all the sheets leading to a single control.


An adjective describing any temporary or makeshift device, such as a rudder made from a table, a mast from an oar, or an anchor from an outboard motor.