Ratings Formula: ORR to PCR
For yachts competing under an ORR certificate, PCR is calculated using the ORR VPP with a Pacific Cup wind mix applied as follows:
|
True Wind Angle |
True Wind |
Distance |
|
Degrees |
Knots |
Miles |
|
Opt. Beat |
16 |
6 |
|
Opt. Beat |
20 |
8 |
|
52 |
16 |
14 |
|
52 |
20 |
22 |
|
60 |
20 |
75 |
|
75 |
20 |
150 |
|
75 |
24 |
75 |
|
90 |
16 |
70 |
|
110 |
16 |
70 |
|
110 |
20 |
50 |
|
120 |
12 |
50 |
|
120 |
16 |
10 |
|
135 |
10 |
100 |
|
150 |
12 |
115 |
|
150 |
20 |
240 |
|
150 |
24 |
100 |
|
Opt. Run |
6 |
20 |
|
Opt. Run |
8 |
40 |
|
Opt. Run |
10 |
80 |
|
Opt. Run |
12 |
120 |
|
Opt. Run |
16 |
135 |
|
Opt. Run |
20 |
300 |
|
Opt. Run |
24 |
220 |
In the table above “Opt. Beat” is the boat’s optimum
wind angle for upwind sailing for the specified wind speed, per the ORR VPP.
Similarly “Opt. Run” is the optimum wind angle downwind sailing.
The result of this calculation is printed on the ORR certificate as "Pacific Cup TOD"
PCR = "Pacific Cup TOD" / .84
NOTES:
The number in the denominator serves several
functions, or perhaps the logic for it can be explained in different ways:
1)
It aligns ORR derived PCR with PHRF derived PCR
2) It corrects for the fact
that boats sail further than the 2070 mile great circle distance.
3)
Historical race data show that it is a better fit for typical time to get to
Hawaii.
The PCR, whether derived from ORR or PHRF represents your expected average "speed" in seconds per mile. If your PCR is 501 for example, in a typical year you should take 501*2070 miles / (24 hrs/day* 3600 sec/hr) = 12 days to get to Hawaii
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