The latest update to the V4 Calculator is also now available: V4H1. It is available for download here
The V4H rule has several improvements, which include the following:
1) Age Allowance:
• The chronological age allowance remains unchanged at 0.2% of rated length per year
• The year has been advanced to 2014 and all existing boats receive an additional 0.2% for 2014
• The maximum age allowance has been increased to 2.02% and will further increase each year by 0.2%.
2) "Pre HPR" allowance
¥ Retain it as is at 3% of rated length for L = 42 feet and under
¥ Linear phase out between L = 42 feet and L = 50 feet
¥ 0 % for L in excess of 50 feet.
This change is because TP 52’s were a base boat design and fit HPR quite well regardless of age, whereas most known older 40-footers are much different from a 40-foot HPR purpose-built boat.
3) All boats with a production sail drive, regardless of age, will have a corrector of 0.9829 of rated length.
This change is because it is currently 0.9829 for 2012 and earlier and was previously 0.995 for new boats. Retractable drives or outboard engines are 1.0000. Originally 0.995 was intended to encourage retractable drives, however that is no longer an HPR objective, and 0.9829 approximates a typical production sail drive. 0.995 is felt to be an inadequate credit for the extra drag.
4) Previous “Maximum crew weight” has been redefined as Base crew weight and remains at:
CWb = -0.26304*L^2+114.1243*L-588.2
Crews must declare the maximum crew weight they will sail with and will be rated for that crew weight. The HPR crew weight typeform calculation has been changed to increase the assessment for large crews on rated length.
5) The robust mast section contains a corrector to encourage at least a 15-degree sweep on the cap shroud chainplates. This section has been greatly simplified. The default corrector for 15 degrees or greater sweep is 1.0000 of rated length. For in-line spreaders it is 1.0100 with a linear proration for any sweep between 15 degrees and inline. While HPR specifies a way to measure sweep, that has only been measured on a few boats. Most boats have 15 degrees or greater sweep, but failure to enter sweep data into the calculator assumes the spreaders are inline. As a temporary measure, default data has been entered for all boats that yields a sweep of 15.11 degrees.
6) HPR allows VCG to be calculated by inclining and a hull file, or by the weight of individual components. This section is now complete. If a boat has been measured by both methods, they are averaged. HPR will review the statistics from time to time and update the calculation as needed so one method is not favored over another.
7) Anywhere the word “Rating” appeared in the spreadsheet it was changed to “Rated Length.” This is to avoid confusion because “Rating” can also mean TCF or seconds per mile.
8) Boats without valid HPR certificates have been deleted from the database.
9) Reduce the minimum LP relative to J to 95% of J.
10) The Certificate page is watermarked for Demonstration purposes only - official certificates used for racing will be issued only by the Rating Authority.
Items under discussion for V5:
1) Wind range - Right now HPR just considers WL 10-12. For V5 it will test some alternatives such as a bell curve of TWS = 8-20. This would make HPR more sensitive to low wetted area (light wind handicaps are greatly affected by that) and including 20 knots would give more weight to planing ability.
2) Cost Control
¥ High cost should not be the only way to race HPR
¥ Good ways to encourage production builders?
¥ Establish a "Base Boat" for materials, processes, and features
¥ Establish credits and charges (assessments) either side of this base boat
Assign credits or charges to those materials, processes or features that will encourage similar levels of cost control in the various size ranges. Those credits are more psychological in nature than technical. An overview of the items for consideration can be found in Appendix E of V4H.
3) The sizes for production sail drives are in steps but HPR is a continuum. Consider modify the prop corrector with a ratio between L and PIPA to account for the fact that a given size production sail drive will have a different effect on a 38 footer than a 40 footer.
4) Re-word spreadsheet and Class Rules to be consistent with the Equipment Rules of Sailing (ERS) and the International Measurement System (IMS). These changes are part of the effort toward the UMS.
A complete guide on use of the HPR Calculator is availabe in Appendix C of the HPR Rules: How to Calculate an HPR Rated Length.pdf
For earlier updates, read more below:
Previous rule versions and explanations
V4H was used to rate boats for Quantum Key West 2014.
Other previous versions:
The V4G version was used for Sept-Dec 2013 and corrects an error in computed age allowance corrections made in previous versions, with a 0.2% per year credit on rated length.
This version also utilizes data gathered on component method measuring to determine VCG. More data is being gathered to make further calibrations to this method.
Lastly, the 3% pre-HPR design credit given to boats with design dates prior to 2012 will not be extended to boats over 15.3 m (about 50 feet) in length.
And a summary of the previous rule changes in the V4f1 rule calculator is available here:
*Note: When you enter boats, be sure to start in a column on the "database" page and assign each boat a number in row 2 (green). Then after the column is full in the database, enter the green number in Cell T4 on the "certificate" page. It automatically fills in the certificate for you. That way you can change quickly between boats just by changing the number in T4.
See the What do I rate or Fleet ratings page for the latest rating calculators used in recent events.
Here is the presentation made to the Yacht Racing Design & Technology Symposium in Dec 2011, in PDF and Powerpoint (note: DOCX) formats: