How long a walk takes, and why we say "at least"

The rule Naismith's rule, 1892

William W. Naismith published it in the Scottish Mountaineering Club Journal in 1892 and it is still on trailhead signs: allow one hour for every 5 km you walk, and another hour for every 600 m you climb. It is old, it is coarse, and it is the reason a figure on this site is comparable with a figure on a sign.

We apply it to the route's own surveyed line and to the climb read off the published contour layer along that same line — never to a straight line between two points, and never to a distance somebody estimated.

It errs long, deliberately Two places we decline to flatter a walk

No credit for going downhill. Langmuir's well-known corrections subtract ten minutes per 300 m of gentle descent, and add ten minutes per 300 m of steep descent. We apply neither. The discount is the half that would make a walk look shorter, and it is also the contested half — it depends on the slope of each individual pitch, which needs better ground data than a contour layer gives. Understating a walk is paid for by whoever takes it, so we leave both out and say so here rather than assuming it quietly.

The return leg climbs what you came down. A fall at the bottom of a gorge is a pleasant walk in and a climb out. The round-trip figure reads both the ascent and the descent of the outbound leg for exactly that reason, and the round trip is the number we cap — because the walk out is not the commitment. What commits you is getting back before dark.

What the figure is not Read this before planning a day around it

It is a floor on walking, not a forecast of your day. Nothing is counted for rest, water, food, photographs, navigation, scrambling, a creek running higher than usual, a track that has not been cleared this season, or walking with children. Naismith describes a fit adult moving steadily on reasonable ground.

Where the contour layer does not cover a route's ground, the climb cannot be measured and the figure is flat-ground time alone. That is flagged on the route rather than folded into the number, because on a range track it is not a small difference.

The 8-hour limit A stamp, not a filter

The policy sets 8 hours as the longest round trip this site presents as a day walk. It is not a claim that longer walks are impossible or unlawful — it is roughly the walking that fits in a day with daylight either side of it.

A walk over the limit is stamped, never dropped. The route publishes in full — its legs, its tenure, its length and its estimate — and carries a notice saying it is longer than a day and what to do about that. The place it leads to says the same thing above its badge. Removing the walk instead would leave the place reading as somewhere nothing was found, which is a different claim and a false one.

Nothing on this site currently passes the limit: the longest round trip in the published data is under four hours, because a walk is only searched for within two kilometres of a fall. The limit is here so that widening that search cannot quietly start presenting twelve-hour walks as afternoons out.

The limit is a fixed number, not a calculation from sunrise and sunset at the place on the day you visit. Two builds over the same records have to produce the same site, and a limit that moved with the calendar would mean walks quietly appearing and disappearing between builds. Check the actual daylight yourself, and remember that a gorge is dark well before the sky is.

What this page will never do

• No user pins

  Every fact here traces to a government layer or a statute and carries a grade, A to C. Community names are quarantined at grade D and labelled as such. Nothing on this page was dropped on a map by a stranger.

• No invented lawfulness

  Where tenure cannot be confirmed from the public record, the page says so instead of endorsing the route or quietly hiding it. Where no lawful corridor exists at all, none is published — the refusal is the answer.

• No safety pretence

  A tier is a tenure verdict, not a difficulty or safety rating. Unmanaged terrain, cliffs and flash flooding are not in the cadastre. The engine reads land records, not the weather.