Measure the boat. Compare the model.

One sheet for LW engineers, followed by a running-trim comparison. Blank fields mean unknown—not zero.

Current reference only: 4,100 kg estimated (3,600 dry + 200 fuel + 300 people/load), 2,750 mm CG estimate with unknown datum, one Volvo Penta D6-340, reported H6 propellers. H8 suitability is unconfirmed. None of these estimates is entered below as a measurement.

Import filled sheet

Entries stay in this page until exported. They are not uploaded or automatically saved. Export before closing.

1 · Identify the boat and loading

Boat / hull numberMeasurement dateDrawing / CAD revision Measured loaded mass (kg)Weighing method / evidenceMass uncertainty (± kg) Dry boat / equipment mass (kg)Fuel mass (kg)Water mass (kg)People mass (kg)Cargo / extra equipment (kg)Other mass (kg) What dry mass includes; tank fills, people/cargo positions, uncertainties

Complete every mass component, entering 0 only where confirmed absent, to check the total.

2 · CG, drafts and closed hull

Mark these reference points on a side-view drawing. Use the same known loading for CG and drafts.

Longitudinal CG distance (mm)LCG datum / directionCG method / uncertaintyVertical CG height (mm)Vertical datumMarked drawing / evidence referenceBow draft (mm)Bow station / reference planeStern draft (mm)Stern station / reference planeWater density (kg/m³)Density measurement / assumptionSealed hull / opening review, especially artificial CAD closures near loaded waterline

3 · Drive and propellers

Engine model / serial referenceDrive model / plate referenceReduction ratioForward propeller markingAft propeller markingPhotos / evidence referencesThrust-line position (x / z, mm)Position datum / axesThrust-line angle / trim zero definitionReviewer, evidence and remaining unknowns

4 · Measured versus assumed-model running trim

This compares measured bow-up hull angle with the existing calm-water model at the entered speed and mass. It does not predict speed from RPM or compare fuel consumption. The model assumes CG at its reference buoyancy centre and VCG 0.8 m; the measurement sheet does not change that model.

Until CG, drive geometry and hull closures match the real boat, differences below are provisional benchmark differences, not validation errors. No automatic fitting or pass/fail judgement is applied.

Load an existing observation / log backupImported observation

Use Export observation JSON or the JSON backup from the cockpit's sea-trial log. Importing does not edit the shared log.

Run ID / reciprocal pair referenceIntended useObserved time / instrument reference Measured GPS speed (kn)Measured loaded mass (kg)Measured running trim (° bow-up)Trim measurement uncertainty (± °)RPM (context only)Fuel flow L/h (context only)Drive trim setting / unitsWave height (m, observed)Calm, steady interval?Instrument zero / reference, loading, engine/propeller, wind/current and notes

Enter speed, mass and running trim to see a provisional comparison.

Only 20–40 kn and 3,600–4,500 kg are covered. Intermediate points use bilinear interpolation of settled numerical benchmarks; no extrapolation. GPS speed is over ground, so current can create a mismatch with the model's prescribed speed through water. Log reciprocal runs separately.

Comparison records

Calibration and held-out validation records remain separate. If a held-out run informs model tuning, reclassify it as calibration outside this review and collect new independent validation data.

Run	Use	Speed / mass	Measured trim	Benchmark trim	Measured − benchmark	Context

No measurements added.