Annie Hill wrote:

Dave Zeiger wrote:Common Acronyms:

Abbreviations, please, Dave.  An acronym is a word formed from the initial letters of other words, eg AIDS

Actually, these are all acronyms, made up, as you say, of the initial letters of the principal words they represent.

I've capitalized the principle letters in the transliteration. The exceptions are PPI (which should rightly be PPII, but is not used that I'm aware), Dmin (which is only half an acronym), and S (which would be SP if it were a true acronym). 

Minor words are often skipped, as in USA (for US of A).

Still, as acronyms are abbreviations (though not always the reverse), I have no objection to either heading.

CE: Center of Effort -- The averaged locus of the forces developed by an airfoil (sail).

Is a junk sail an airfoil?

Hmm... I'd say so, as even flat sails develop airfoil through stretch, batten bend and twist. But it could be confusing.

We could start with the design definition and deemphasize the point:

CE: Center of Effort -- The geometric center of sail area(s), drawn flat. In practice, the CE is the locus of sail drive, and adjusts with sail trim.

CLR: Center of Lateral Resistance -- The averaged locus of a hull's underwater, profile silhouette.

Dmin: minimum Drift -- The minimum drift required for full and proper function. [PJR pg. 63]

DWL: Design Water Line -- The water line at which a vessel at which a vessel is designed to float.

Design or Designed?

All the references I found say 'Design' when deconstructing the acronym. In textual elaborations, 'designed' is used in the body of text. It's possible this is American usage, though google returns from British designers were the same.

LOA: Length Over All -- A vessel's length, as measured from the foremost to aftermost components. Many harbor's charges are proportional to the LOA.

LOD: Length on Deck -- A hull's length as measured from bow to stern.

LR: Lateral Resistance -- A vessel's resistance to athwartships motion through water.

LWL: Length Water Line -- Length of a hull measured at the waterline (see WLL).

LWL: Load Water Line - See DWL, which term is now more commonly used.

P: Panel -- The height of a JR panel. Used in PJR for calculations of sail geometry and rigging components. Exact determination varies by context. [PJR fig. 2.20]

PSI: Pounds per Square Inch -- Common unit for measuring pressure.

PPI: Pounds per Inch of Immersion -- Pounds of lading required to raise a given hull's WL one inch.

PJR: Practical Junk Rig -- Book by HG Hasler and JK McLeod.

S: Sling point -- The point from which the yard is hung from the halyard. [PJR Fig. 6.8]

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.

WLL: Water Line Length -- Length of a hull measured at the waterline (see LWL and DWL).