Every figure on this site is meant to be traceable to a manufacturer's own published specification, converted into comparable units. This page is the rulebook — including the places the data currently breaks it, named, because publishing known gaps is what a research instrument does and a content farm never does.
What the dataset is
1,003 hydrofoil front wings from 23 brands, gathered by reading each manufacturer's spec pages and converting what they publish into true area in cm² and span in mm. Axis and Sabfoil number their wings by span in millimetres; Lift and Unifoil by square inches; most others by area under an unstated measurement basis. None of those numbers are comparable as printed. The conversion is the work. Data current to August 2026.
The sourcing rule, and its violations
A figure may come from the manufacturer's own site and nowhere else. Retailers, distributors and reviews re-round, drop columns and carry last season's spec. Every row carries the URL it was read from and whose page that is.
95 rows currently violate this rule, and they are not hidden: Slingshot (32), Takuma (18), Lift Foils (13), Armstrong (12), North (7), Ozone (7), Unifoil (4), Duotone (2). They stay until re-sourced from the brands' own pages, and no new row is allowed to join them — the standing preference is a blank cell over a retailer's figure.
Aspect ratio is checked, not transcribed
Every published aspect ratio is reconciled against the wing's own geometry: AR = span² ÷ area. Within 5% it is confirmed — 892 rows. Between 5% and 10% it is flagged as differing — 23 rows. Beyond 10% the geometry wins, the published figure is discarded, and the row is filed as a brand data error — 15 rows. Where the span itself was back-derived, the check is circular and the row says "unverified" instead of pretending.
What the dataset knows it does not know
771 of 1,003 rows do not state whether their area is projected or flat. The two run 3–8% apart, so any comparison tighter than that — including this site's own ±5% equivalence matches — may be comparing unlike figures. That is what the straw mark under an area means, here and on every page: a figure the project cannot fully stand behind, said out loud.
No stabiliser or fuselage data. No rider-weight maths — both axes are fixed properties of the wing. And nothing here is a riding impression: Fast Bobby is the researcher, never the reviewer. The site publishes what the manufacturers claim, made comparable, and stops there.
Equivalence, precisely
A wing's cross-brand equivalents are every current wing from a different brand within ±5% of its area and ±8% of its aspect ratio. Same-brand neighbours are excluded — they are the brand's own size steps, not an answer to "what is the other brand's version of this wing".
Report an error
If a figure here disagrees with what a manufacturer currently publishes, that is exactly the report worth sending: name the wing, the figure, and the page it came from, via the contact address. Every wing that has its own page carries a link to the manufacturer page its figures were read from, so a correction can point at the same source the row does.
Updated 2026-08-11