This is the engineer talking, not the “surfer/lover/feeler/groover”, which invariably leads to horrible foils for general surf use. Listen to Adrian from Axis talk about all the engineering led development and then ask a surfer what they think of his foils and they mostly don’t love them because they are so abrupt and “efficient” (notwithstanding the newest one which I haven’t tried). If you design a foil for maximum efficiency, you maximally ruin the surf experience, which is Jondrums point. I confirm this by “ruining” a few stabs, and they are without doubt much better for riding waves, which is also what the Silk is designed for. Smooth, predictable, stable, fun. This is where the tubercles make me wonder that there are actual benefits.
Yes I shared the thread verbatim. I just now asked a series of follow ups which reduces it to the one’s you’d expect, and then refined in on surf specific, and asked for balanced take not just criticisms, which seems relatively balanced and aligned:
The most honest balanced conclusion for surf carving
- If your priority is maximum glide / pump / top speed, tubercles are a risky bet because drag penalties are common and documented in full-scale tow testing of at least one configuration. (Strathprints) [The moth study]
- If your priority is control in turbulence + robustness to breach/ventilation + smoother unsteady loads, there’s a credible, evidence-backed story that tubercles can help by:
- attenuating drag-force fluctuations in wave-driven unsteady flow, (arXiv)
- moderating dynamic stall (less impulsive vortex-driven events), (Springer Nature Link)
- and weakening/diffusing the tip vortex (a known air-ingestion pathway). (arXiv)