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How it works
Everything on this site is either a published measurement, an assessment we made and will defend, or an arithmetic consequence of the two. This page says which is which.
Where the numbers come from
Length, beam, deck height and layup weights are taken from the manufacturer, and where a maker publishes nothing we say so rather than estimating quietly. Prices come from dealers in the markets we cover, in the currency the dealer actually publishes, and the footer carries the month they were last checked. A converted price is marked as converted, because a conversion is not a shelf price.
Stability and speed are our opinion
The two scores out of ten are editorial. They are built from hull dimensions, independent reviews and owner reports, and every craft page carries the reasoning beside the score so you can disagree with it on the evidence. They are not manufacturer claims, and they are not an average of user ratings. There is one reviewer and it is us.
Both scores are rated at the hull's own design weight. This is the part most comparisons skip. A ski rated 8 for stability is rated 8 for the paddler it was drawn around; put someone 20 kg heavier in it and the boat sits lower, loses freeboard and behaves like a narrower hull. The number has not changed but the boat has.
Where the speed score has a hull behind it
On 39 craft the speed score is not only a reading of the reviews. We traced the hull off the maker's own side and plan photographs, scaled it against the published beam, and solved it: sink the hull to the waterline its design load puts it on, then read the wetted area, the way the volume is spread along the length, and the drag both of those imply at a fixed 160 watts. That produces a speed the shape alone argues for, owing nothing to what anyone wrote about the boat.
To test it we hid an entire brand from the fit and asked the model to rate that brand cold. The shape terms cut the error against our own scores from 1.14 points to 0.88, and none of 200 matched searches over random variables managed the same. So the measurement carries real information. What it cannot do is correct us: it was fitted to our scores, not to a stopwatch, so it can average out our noise and not our bias.
Which is why the published number moves a third of the way from the editorial score toward the modelled one and no further. That fraction is what the two error bars justify: our own scores are set on a half-point grid and carry about that much noise, and the model carries about three quarters of a point. In practice the move is a tenth or two on most craft and half a point at the extreme, and every craft it touched says so on its own page.
The same score, at your weight
Because the score is rated at the design weight, it answers a question about the hull rather than a question about you. Where the two come apart we show a second number beside it: the stability rating adjusted to the weight you set. It is worked out from the hull's own geometry, by solving for the waterline your mass puts the boat on and taking the metacentric height there against the one at its design weight.
It only ever reads lower, and that is deliberate. Loading a hull past its design weight sinks it, and the physics and the owner reports agree about what that feels like. Below the design weight they disagree: the arithmetic hands a light paddler a stability bonus, while the paddlers themselves describe the opposite, a boat they cannot sink that rides high and washes about underneath them. That complaint is about seat fit and freeboard, not about metacentric height, and nothing published would let us put a number on it. So we do not. Under the band you get the weight-fit warning in words and the rating is left alone.
Scroll the diagram sideways to see all of it
BM = 0.0379 × L × b³ ÷ ∇ carries displacement on the bottom. That is the whole of the second number. The site never shows either curve reading directly — the curve is a fit across the whole index, so only the gap between the two is used: 2.2 points, taken off this hull's editorial 7 to give the 4.8 a 115 kg paddler sees on the card.The paddler weight band
Every craft carries a design weight worked out from its own dimensions rather than from a marketing range:
design = 109 × L × B × H − boat weight − 2 kg kit
L, B and H are length, beam and deck height in metres. The constant is calibrated against the paddler limits Fenn publishes for hulls where we have both the dimensions and the maker's own figure. Doubles use a higher constant and are quoted per seat.
Where a maker publishes its own limit we show that too, and where the two disagree by more than about 15% we say so and let both bracket the answer. Hulls under five metres are flagged, because the calibration weakens at that end and the maker's figure is the better guide. A deck height we had to estimate is marked, and is worth roughly ±5 kg either way.
The band around the design weight runs from 0.88 of it to 1.06, with the ideal window between 0.93 and 1.02. Outside that is not a prohibition. Plenty of people paddle boats they are technically too heavy for, and do it well. It is a statement about where the hull was drawn to sit.
Scroll the diagram sideways to see all of it
What we do not do
We sell nothing, hold no stock and take no commission on any link. There is no second-hand pricing here, because a used-boat market is local, seasonal and far too thin to average honestly. And we do not rank craft against each other overall, because "best surfski" is not a question that has an answer without a paddler attached to it.
Craft that are no longer made
Discontinued craft stay in the index but live in a separate section, out of the finder and the main listing. A second-hand Fenn Elite is still a boat someone is deciding about, but a shortlist that hands you something you cannot buy is not a shortlist.
Corrections
If a figure here is wrong, it is worth telling us, particularly if you are a maker and we have your own boat's dimensions wrong. Every craft page lists its sources so you can see what we were working from.