FAQ
Foilbench is an interactive pump-foil simulation for comparing foil setups. This FAQ answers search and practice questions about numbers, limits and workflow.
What is Foilbench — and what is it for?
Foilbench computes hydrofoil physics for pump foiling (quasi-steady polars with Theodorsen/Garrick corrections) and answers: What changes if I swap this part?
Use it to compare setups, explore trim/pump and learn the metrics — not as a substitute for water time or CFD.
→ What is Foilbench? · Open the simulation
How do I find take-off and setup differences before testing on the water?
- Load the reference or your own setup
- Swap front wing / fuselage / mast
- Read metrics (take-off, best glide, Vmax) and panel D
- Optionally remember a setup and overlay curves
Comparisons under the same rider/water/pump conditions are more reliable than single numbers.
→ Compare setups · Getting started
Foilbench vs. on-water testing — what does the simulation replace?
Nothing completely. Foilbench ranks options and makes trade-offs visible (take-off vs. cruise, pump demand, Vmax). Waves, chop, wind and individual technique stay on the water. Use the simulation to narrow choices; confirm at the spot.
Are absolute numbers (km/h, watts) realistic?
Approximately, but not calibrated to your sessions. Friction assumptions, keel water and individual technique are not modelled.
Comparisons between setups under the same conditions are much more reliable.
Why do my on-water experiences differ?
Possible reasons:
- The model has no waves, chop or wind
- Surface proximity at the wing is simplified
- Friction is not calibrated to manufacturer data
- Your technique (timing, body span) differs from the modelled cycle
What is metabolic power?
A rough factor on mechanical power — muscles are not 100 % efficient. Use for comparison, not as an exact ergometer reading.
What is Vmax — and why does it differ from my GPS top speed?
Vmax is the highest useful steady ride speed in the model: still trimmable and L/D at least 40 % of peak. GPS peaks from a session (pump spikes, downtilt, surf) are a different quantity.
The subline (watts) is power at the Vmax point (drag × speed), not a sustained power budget. Goal Speed (Advanced/Pro) moves the analysis marker there.
Can I save my setup?
Saved comparison setups persist in the browser. There is no cloud account — export via screenshot or notes.
Where do setup costs come from?
From the manufacturer catalog (YAML baseline) and optionally a live fetch of product URLs. Prices are indicative; partner brands often show only the dealer path without MSRP. Details: Setup cost.
Missing brand in the catalog?
Contributors find instructions in the project's GitHub repository.
API documentation?
Interactive OpenAPI at Swagger on the same host as the simulation (/docs — not to be confused with this guide).
Is Foilbench free?
The simulation is free to use. An optional support link funds hosting and development.
How can I give feedback?
Use the Feedback link in the simulation footer. Requests and bug reports reach us privately — there is no public wishlist or ticket status.
Liability
WARNING
Information may contain errors. Please verify everything yourself. No liability is accepted for correctness.
Technical questions about the model
→ Glossary