SAILING MODEL AND OBSERVATION WORKSHEET
Save in a text editor. Duplicate the OBSERVATION block for each steady
interval. Preserve original logs. This is a learning record, not navigation
or operating instructions. Label invented, predicted and measured values.

QUESTION AND MODEL
Question: ___________________________________________________________
Boat configuration/loading/sails: ____________________________________
Software/version: __________  Polar source/version: _________________
Wind definition: true / apparent; reference details: _________________
Speed definition: through water / over ground: _______________________
Input units and sensor calibration status: __________________________

OBSERVATION
Interval start/end/timezone: _________________________________________
True wind speed (kn) and angle (degrees), if matching the model: _______
Predicted boat speed (kn): ____  Observed matching boat speed (kn): ____
Observed / predicted x 100 (%), if prediction is positive: ____________
Current/sea state/loading/sail configuration: _________________________
Sensor or maneuvering issues: ________________________________________
Excluded samples and reason (retain originals): ______________________
Interpretation and next check: _______________________________________

Fictional example: 6.0 / 6.4 x 100 = 93.75%, approximately 94%.
An over-ground reading of 6.7 kn measures a different reference from
6.0 kn through water; resolve current and definitions before comparing.

OPTIONAL ROUTING RECORD
Forecast model/issue time/valid times: ________________________________
Departure time/timezone and route constraints: _______________________
Polar and software settings: ________________________________________
Alternative forecasts/settings and result differences: _______________
Independent navigation checks and responsible skipper: _______________

Model source: https://orc.org/for-designers/orc-vpp
Polar explanation: https://data.orc.org/public/samples/Speed_Guide_Explanation.pdf
Routing documentation: https://www.expeditionmarine.com/downloads/documents/Expedition.pdf
Full guide: https://yenra.com/modeling-software/
Prepared September 18, 2026. Keep model versions and source definitions.