How we rank, and what we have not done
This page is the equivalent of the "How We Tested" section our competitors run. We have tested nothing, so it says what we did instead -- precisely enough that you could repeat it.
What we do not do
First, plainly, because everything after it depends on you believing this part.
- We have not paddled any of this gear. Not one boat, not one board, not one pump.
- We own no units. There is no test lab, no test pond, no gear cupboard.
- We accept no free product and no loan units.
- We take no payment for placement. No brand has paid to appear here or to appear higher.
- We make no credential claims. Nobody here is a certified instructor, a guide, or an engineer, and no page will imply otherwise.
Five of the eleven ranking competitors measured during our research put "Tested" in their page titles. We never will. That constraint is not a weakness we are working around -- it is the reason this site is built the way it is.
What we do instead
1. Compile published specifications
For each product we read the manufacturer's own product page, spec sheet or owner's manual and record: weight, complete system weight, packed dimensions, inflated dimensions, capacity, working pressure, floor pressure, volume, material, chamber count, valve type and warranty term.
Where a manufacturer page is unavailable or incomplete, we use a specialist retailer republishing the manufacturer's figures, and we cite that retailer rather than pretending it came from the brand. We never cite another affiliate publisher as a source for a specification -- competitor pages are competitive intelligence, not references.
Every citation carries the date it was read. Specs change between model years, and a citation without a date is half a citation.
2. Compute the figures nobody publishes
This is the part that makes the site worth reading. All of it is arithmetic on published inputs, so all of it is checkable.
Packed linear inches
length + width + height. The measure every US airline uses for a checked bag, where 62 inches is the economy line. Computed for the 7 products whose makers publish packed dimensions.
Packed volume
length x width x height, converted to liters. This is what turns "most compact" from an adjective into a ranking, and it answers a different question from linear inches -- a car boot cares about bulk, an airline cares about the sum of the edges.
Free air required
V x (14.7 + P) / 14.7, where V is the chamber volume in liters and P is the target gauge pressure in psi. The V fills the shape; the V x P / 14.7 compresses it to pressure.
Hand-pump stroke count
Modeled in two phases, because that is how a dual-action pump works. Below the switchover it moves air on both the push and the pull, delivering two cylinders per full cycle; above it, one.
strokes = [V x (14.7 + 7) / 14.7] / (2c) + [V x (P - 7) / 14.7] / c
where c is the pump's published cylinder volume in liters. Computed for the 5 products whose makers publish both a volume and a target pressure.
Electric pump minutes
V / stage1 + (V x P / 14.7) / stage2, using the pump's two published flow rates. A single-stage pump uses its one rate for both terms.
Airline verdict
Packed linear inches against 62, and complete system weight against 50 lb, as published by United, Delta and American. Both limits have to be cleared; clearing one is not enough. Where a manufacturer publishes only a hull weight and not a system weight, we say so and hedge the verdict accordingly -- which is why several rows on the flying guide say "probably" rather than "yes".
3. Publish the caveats with the results
The inflation model is deliberately simple, and every page that uses it prints these next to the numbers:
- Air is treated as an ideal gas at constant temperature. Real pumping warms the air, so a chamber that reads 15 psi while you are pumping will read slightly under once it cools.
- The chamber is treated as rigid at its final volume. Drop-stitch boards are very close to this; round kayak tubes stretch a little as they come up to pressure, so their real figures run slightly higher.
- Hose volume, valve losses and the air that escapes each time you disconnect are ignored.
- Dual-action hand pumps are assumed to move a full cylinder on both strokes below 7 psi and one cylinder per stroke above it, which is what their manuals describe.
- Every figure is a planning estimate built from published specifications. We have not timed any of this with a stopwatch, because we do not own any of this gear.
4. Verify the product can actually be bought
A model only becomes a ranked pick if it is currently sold on Amazon. A comparison whose buy button cannot exist is not a comparison, it is an advertisement for something you cannot have.
Brands that sell direct only may still appear in editorial context -- in a comparison or a guide, as background -- but they do not occupy a top-pick slot.
5. Name something to skip
Every roundup on this site names at least one product not to buy for that page's purpose, and says why. A list where everything is great is a list nobody believes, and it is usually a list assembled by commission rate rather than by criterion.
Several products appear as the skip pick on one page and the winner on another. The Advanced Elements PackLite wins the travel ranking and is the skip pick for beginners and for fishing; the iROCKER Nautical is the skip pick for fishing and the disclosure winner on the budget page. That is what it looks like when a ranking is genuinely per-criterion.
- 20 products with full published specifications compiled and cited.
- 7 with a published packed size, checked against the 62-inch airline limit.
- 5 with a published volume, so the pump load could be computed.
- Zero products tested, zero free samples accepted, zero paid placements.
How ranking criteria are weighted, by page type
| Page type | Ranked on | Why |
|---|---|---|
| Travel roundup | Packed linear inches | It is what decides whether the thing gets on the plane |
| Lightest roundup | Published weight | The stated subject of the page |
| Beginners roundup | Width, then volume | Stability is what a first hour needs |
| Fishing roundup | Capacity or rider limit | A loaded boat near its rating handles badly |
| Two-person roundup | Capacity | The constraint that separates otherwise similar tandems |
| Pump roundup | Published pressure ceiling | A pump that cannot reach your target is not a candidate |
Our conflicts, stated
Stroke & Stern earns money when a reader buys something through a link here. That is the entire business model and the disclosure page sets it out in full.
The structural point worth making: every product on this site links to Amazon, tagged with the same Associates ID. There is no higher-paying merchant to steer you toward, because we have joined no other networks. If that changes, this page will say so before any link does.
What we can promise beyond that is thin and we would rather be honest about it than dress it up: commission rate does not affect ranking order, no brand has paid to appear, and no free product has been accepted. You are entitled to weigh those promises against the fact that we benefit when you buy something. The published method above is what makes them checkable rather than merely stated.
Corrections
If a figure here is wrong, we want to know, and we will fix it visibly rather than quietly. The contact form has a spec-correction option and the editorial policy covers how corrections are handled. Specs change between model years; if you are looking at a product page that now says something different from ours, that is exactly the message to send.