Hello ZhuHai,
If you go to Kemp Sails website and download their sail measurement form
http://www.kempsails.com/yacht-sails/measurement-forms/1-kemp-sails-yacht-measurement-form/file.htmlthen the following measurements will make sense:-
Section 1: Mast and Boom
P: maximum luff length. 12.36m. The length P was taken to maximum halyard hoist.
H: Approximate width at mast top 300mm (estimated from deck level using the mast width as a guide).
E: Maximum Foot Length. 4.165m This measurement was taken to the black band on the boom.
C: Backstay to end of boom casting horizontally 1100mm
D: End of Boom to Black band/Clew. 298mm
X: Tack attachment set back from mast 90mm
Z: Reef Horn set back from mast
I don't think I've got one of those.
Y: Top of boom to Mast Gate/Sail or Slider entry. 620mm
BAD: Top of Boom down to Mast Base. 1105mm
Section 2: SAIL SLIDER IDENTIFICATION HA458
Section 3: MAST BEND
A: PRE-BEND (Backstay OFF) at 25% 50mm. at 50% 80mm at 75% 70mm
B: Max Bend (Backstay ON). at 25% 80mm. at 50% 140mm. at 75% 100mm
Their Quote Mainsail Special Price including 15% discount and VAT £1664.51
Up and over leech line adjustment. £ 110.99
Full Batten System with 5 full length battens with Rutgerson
wheeled Slider Cars, articulated linkages, & Adjustable Luff Boxes. £ 561.00
Carriage. £. 43.38
At the time I was in no hurry for the sail to be delivered and construction started approximately four weeks after receipt of my order with delivery to my home about three weeks later. The sail was constructed from a Premium High Tenacity Polyester material said to be "ideal for offshore cruising."
During construction I requested a third reefing point which added a further £93.92 to the overall cost.
I've had the sail now for two years and I've been very satisfied with every aspect of it from performance to appearance it has been so much better than the partially battened sail it replaced.