| NEW OFFCHART RACER FUNCTIONS IN 2006
EDITION |
| Offchart Racer was introduced to provide the primary functions
for long-distance racing at a very competitive price. With the added functions in the 2006
Edition, "OR" now offers ALL of the features of much more expensive tactical
programs, and superior tactical computations. Only Local Knowledge offers the "Best
Tack" function, which goes far beyond the "what-if" feature of competitors.
SEE DETAIL With the 2006 Edition, you have all the tools necessary for any kind of
racing. Only our "Force 4" tactical program includes more functions and
displays. [For summary of Force 4 features, CLICK HERE] |
| NEW DATA
INTERFACE: "OR" now reads and interprets all instrument data, in NMEA or Ockam
format. The interface form allow you to select input and displays the current values as
they are received. Selected values are displayed in the "OR" datastrip (shown
along left side of the display). You can click on the datastrip to shift it to the right
side, or click anywhere on the screen to hide (or recall) it. The measured wind values
automatically adjust the "default" values of course solution and routing
functions. |
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| "OR"
NOW BUILDS POLAR FILES: you can save wind and boat data to build and improve the polar
file for your boat. The boat data file is input to the "polardo" facility, which
converts it to the polar format used by "OR." This facility also allows you to
type in spreadsheet values to create an initial polar file. |
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| NEW
"OR" 'BEST TACK' FUNCTION: The most common situation in racing is tacking to an
upwind mark (or jibing to a downwind mark). The only tactical information provided by
other software is typically referred to as a "what-if" function. This computes
times to the mark for an approach via either layline (first a port tack, or first a
starboard tack). The image below shows the result of a typical "what-if"
computation, using the 'Enter Data' option button on the new OR "Best Tack"
interface. The form fills in the latest wind data, but allows you to change it to see the
effect of a windshift. The form also fills in average current across the venue drawn from
the "Local Knowledge" current model. You can modify average current, to see how
this affects results, or enter values from scratch. When current varies across the venue, it changes both the
"true" wind experienced by the boat and adds directly to boat velocity. In
general, this will result in an advantage to an approach via one layline or the other.
Other program "what-if" computations use an average current across the
venue. This greatly simplifies the calculation but washes out the difference between
tacks. In this example the blue lines show the layline as it would be with zero current,
and the red lines show the result of the "what-if" calculation. The magenta
dots, however, show the actual laylines, which are curved as the result of differences in
current point to point (here current is shown by the blue vectors). Only Local Knowledge
programs compute the true laylines, which result from differential currents across the
venue. |
| RESULT OF TYPICAL "WHAT-IF"
SOLUTION, UPWIND AGAINST 2 KNOTS OF OPPOSING CURRENT |
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| COMPARE TO OR "BEST
TACK" RESULT: When you average current, the time via either layline is always
the same. In reality, there can be very significant differences. In this example (using
J35 polars), the exact result shows an advantage of ALMOST 3 MINUTES for a initial port
tack followed by an approach along the upper, curved layline (below). When you click the
"Use Instrument Data" button, the "OR" "best-tack" function
uses the current model and the latest instrument data and does the full computation. The
result identifies the port tack solution as optimal (note that time to the mark is also
significantly different from the "what-if" result above). The solution
automatically updates as you sail. |
| RESULT OF OR'S "BEST TACK" FUNCTION,
FOR EXACT SOLUTION SHOWING PREFERRED APPROACH |
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| NEW
"OR" STRIPCHARTS TO PLOT DATA AND COMPARE TO PREDICTIONS: Other tactical
programs provide "stripcharts" that track instrument data over time. You can use
these charts to monitor windspeed and direction in order to anticipate what changes may
lie ahead. OR stripcharts do more, allowing you to track and compare actual to predicted
values of wind, current and boat performance. |
| xxxxxxxxxxxxxxxxxxxxxxxxxxx This wind stripchart shows measured wind direction (in upper chart)
and windspeed (in lower chart) taken from the instruments (jagged blue lines). You can
adjust the time interval to show just the more recent values, or the values for the entire
race (here 60 minutes).
You can simultaneously plot the predicted wind
values (say from a wind model or grib file), shown here as the smooth, red lines. This
enables you correct the wind file for routing purposes using the "scale" and
"rotate" parameters. |
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