One listing, two lengths, nearly five feet apart. The gap is not a typo, and only one of the two numbers is the one that decides where she fits.
Neither number was wrong. They measure different things, and the listing did not say which one it was leading with.
We score the overall length (LOA), pulpit and swim platform included — that's the number a slip has to fit and a lock chamber measures. A listing's shorter “Length” is usually hull length, and it isn't the one that decides where she fits.
The pulpit hangs off the bow. The swim platform hangs off the transom. Both are structure, both are permanently attached on most boats, and neither is in the hull number. On a forty-something-foot cruiser the two together can run four or five feet.
So a listing headed 48 ft with Length Overall 52.67 ft in the specifications is not contradicting itself. It is quoting the shorter figure at the top, which is the ordinary thing to do, and the reader who stops at the headline is four and a half feet out.
Length is not a Loop gate. AGLCA's own FAQ says there is no practical length restriction on the route, and the tightest lock chamber on the whole thing, on the Trent-Severn, takes boats up to 84 feet. Nobody is kept off the Loop by being 52 feet instead of 48.
That matters because the two-lengths problem gets talked about as though it were a disqualification. It is not. It is a planning number that turns out to be wrong after you have planned around it, which is a different and quieter kind of expensive.
Paste a listing in and we read both figures out of the text you pasted. If it states an overall length and a hull length, both carrying units, and they are a foot or more apart with the overall figure the larger, we surface it as a disputed claim rather than picking a winner quietly. The finding prints both numbers and the subtraction, so you can check us against the listing you are looking at, and it tells you to confirm the real length with the broker.
Waterline length is deliberately excluded. It is legitimately shorter than both and it is not the same disagreement.
We do not store the answer. It is recomputed from the listing text every time the page is read, so it cannot rot into a stale claim after you correct the boat.
The video walks one real listing through the tool and hits this exact disagreement about three minutes in. It is on YouTube, and nothing on this page contacts them until you ask it to.
We haven't put a tape on any of these boats. Everything on this page is about what a listing says and what the two figures in it mean. The only way to settle what a specific hull actually measures is for somebody to go and measure it, and that somebody is not us.
The route figures come from AGLCA's published FAQ and route pages: no practical length restriction on the Loop, and 84 feet on the Trent-Severn. The worked example is a real brokerage listing read in August 2026; we have not named the boat, the seller or the brokerage, because publishing an unsolicited evaluation of somebody's inventory is a different act from explaining a trap.
If we've got something wrong, tell us and we'll fix it — support@caniloop.net. A correction from someone who has actually run it is worth more than anything we can write.
Next: How tall can your boat be? → The one measurement that can actually stop you, and the one we refuse to guess at.