This section spells out common acronyms one might encounter in discussions related to junk rig. Where indicated, term definitions are entered under their full text in Common Terms Explanations presented here are partial.
AB: Advanced Barge-- Any flat bottom, slab sided barge in which side curvature in plan matches bottom curvature in profile. Side and bottom are approximately equal, reducing cross-chine flow and associated turbulence/drag.
AKA: Also Known As-- Indicates synonymous terms.
AS: Advanced Sharpie-- Concept developed by Phil Bolger. Any flat bottom, slab sided sharpie in which side curvature in plan matches bottom curvature in profile. Side and bottom are approximately equal, reducing cross-chine flow and associated turbulence/drag.
AR: Aspect Ratio-- Proportion of height:width (height to width). Note that in some fields, this proportion may be reversed. See Aspect Ratio.
B: Batten-- Length of batten as measured from one end to the other. Used in PJR for many calculations. See Batten.
BOTM: Boat of the Month.
BR: Bermudan Rig-- The one to 'beat'. See Bermudan Rig.
CB aka CoB: Center of Buoyancy-- The averaged locus of all the 'floaty forces' acting upon a hull. See Center of Buoyancy.
CE aka COE: Center of Effort-- The geometric center of sail area(s) as seen in profile. See Center of Effort.
CG aka COG aka G: Center of Gravity (aka Gravity)-- The averaged locus of the distribution of a vessel's mass. See Center of Gravity.
CL: Center Line-- The central line of a body. In a hull, the center line is longitudinal, and seen in plan view.
CLR:Center of Lateral Resistance -- The averaged locus of a hulls underwater, profile silhouette. See Center of Lateral Resistance.
CMG: Course Made Good. Actual course of a vessel, as distinguished from its heading. Incorporates set from all influences.
CP: Center of Pressure aka CoP-- The locus of maximum force developed by a foil. See Center of Pressure.
DIY: Do It Yourself-- The movement towards self-sufficiency, empowerment and independence. See Do It Yourself.
Dmin: minimum Drift-- The minimum drift required for full and proper function. See Dminand Drift.
DWL: Design Water Line-- The water line at which a vessel is designed to float.
FG: Fiber Glass-- Glass formed in filaments and woven or chopped and matted. Term often extended to include composites formed with resin. American term (see British GRP).
FU: Fan Up-- Raising of panels by wind (not halyard). See Fan Up.
FUP: Fan Up Preventer-- Any system rigged to prevent a fan-up. See Fan Up Preventer.
G: Gravity (Center of)-- see CG.
GR: Gaff Rig-- See Gaff Rig'.
GRP: Glass Reenforced Plastic-- Common boat construction composite material. British term (see American FG).
GSM (Grams per Square Meter):Standard rating for fabric weight.
HK (Parrel)or HKP: Hong Kong Parrel-- See Hong Kong Parrel.
JR: Junk Rig-- Best rig ever. See Junk Rig.
JRA: Junk Rig Association-- Association to promote and develop Junk Rig.
JRG: Junk Rig Glossary-- You are here.
KISS: Keep It Simple, Sailor-- Good advice.
LAP: Length Above Partners-- The distance from a mast's partners to its masthead. See Length Above Partners.
LHP: Luff Hauling Parrel-- Line adjusting the luff. See Luff Hauling Parrel.
LOA: Length Over All-- A vessel's length as measured from foremost to aftmost components. Many harbors charge proportional to the LOA.
LOD: Length on Deck-- A hull's length as measured from bow to transom.
LR: Lateral Resistance-- A vessel's resistance to thwartships motion through water. See Lateral Resistance.
LWL: Load Water Line-- See DWL, which term is now more commonly used.
LWL: Length Water Line-- Length of a hull measured at the WL (see WLL).
NA: Naval Architect-- A certified marine designer.
NACA: National Advisory Committee for Aeronautics-- See NACA Aerofoil.
NL: NewsLetter -- Usually, the JRA Newsletter.
ML: Mast Line-- Centerline of mast. See Mast Line.
P: Panel-- The height of a JR panel. See Panel.
PSI: Pounds per Square Inch-- Common unit for measuring pressure distributed over an area.
PPI: Pounds per Inch of Immersion-- Pounds of lading required to raise a given hulls WL one inch.
PJR: Practical Junk Rig-- Book by HG Hasler and JK McLeod. See Practical Junk Rig.
S: Sling point-- The point from which the yard is hung from the halyard. See Sling Point.
STD: Speed, Time, Distance:-- Speed x Time = Distance.
SMG: Speed Made Good-- A measure of net speed (velocity) relative to a fixed reference (generally over the bottom). Also known as VMG.
TF: JRA Technical Fora-- JRA fora designated for technical discussions.
THP: Throat Hauling Parrel-- Line adjusting the throat and topping up the yard. See Throat Hauling Parrel.
VMG: Velocity Made Good-- A measure of net velocity (speed) relative to a fixed reference (generally over the bottom). Also known as SMG.
WL: Water Line-- 1) The idealized line formed by the intersection of a vessel with the surface of flat water. 2) A line painted or graven, indicating the DWL or other lading lines. 3) In boat design, the line formed at the intersection of the hull and horizontal planes at (any) specified height(s).
WLL: Water Line Length-- Length of a hull measured at the WL (see DWL).
YCB: JRA Yacht Club Bar--- JRA member forum designated for socializing.
YHP: Yard Hauling Parrel-- Line adjusting yard position. See Yard Hauling Parrel.
Source: JR Glossary Project, 2016