Even in summer a sudden fog can lead the most experienced climbers into making fatal mistakes on Britain’s highest mountain.
But yesterday, Britain’s leading adventure magazine, Trail, was at the centre of a blistering attack by mountain safety experts after making a potentially fatal blunder in its recommended route for climbers descending from the 4,418ft peak.
The compass bearing, given to readers for a safe descent from the summit, would take mountaineers directly over the edge of the peak’s North face and to almost certain death.
It is the second time in recent months that Trail has been accused of making a potentially life-threatening mistake in its columns.
In November, it claimed that the 28-mile trek through the Lairig Ghru, in the heart of the Cairngorms, and Stac Pollaidh, an arduous, 13-mile mountain path in Wester Ross, could be free of deep snow "even in the worst winter weather".
Mountain rescue leaders and safety experts condemned the editor, Guy Proctor, and branded the article as irresponsible and potentially dangerous.
The criticism was led by Richard Wild, the mountain safety adviser to the Mountaineering Council of Scotland, who claimed that the article could mislead inexperienced hillwalkers and put them at serious risk.
Yesterday, Mr Wild led this latest condemnation of Trail, following its publication of the Ben Nevis route.
The magazine advises readers to take a compass bearing of 281 degrees from the summit "and stick to it". Unfortunately, the bearing is the second that mountaineers have to take to avoid Gardyloo Gully and the North face. They have, according to every reputable guide, first to take a bearing of 231 degrees and walk for 150 metres, with Gardyloo Gully on their right, before taking a sharp right turn and continuing on a fresh 281-degree bearing.
Mr Wild said yesterday he was astounded at the blunder. He has written to Mr Proctor, highlighting the mistake and demanding that accurate advice be published in the next issue of the magazine.
He said: "This mistake is potentially fatal. If someone actually followed that bearing they would go over the North face.
"If you go from the summit of Ben Nevis and follow that bearing, it would take you right over a sheer drop.
"The descent from the summit in poor visibility is one of the most infamous navigation tasks in the British Isles and the bearings have been widely publicised for many years."
He added: "The potential consequences of following the advice provided by Trail are clear - anyone following a bearing of 281 degrees from anywhere close to the summit cairn or shelter will be taken directly over the North face.
"I find it incredible that Trail has published advice which is so obviously and dangerously wrong. I would hope it’s unlikely that somebody would takes a bearing out of a magazine and go to the top of Ben Nevis and follow it."
Tim Walker, the principal at Glenmore Lodge, near Aviemore, the national mountain training centre for Scotland, said: "Gardyloo Gully is a drop of about 1,200ft.
"If you follow the bearing as given by Trail magazine, you will have a long time to consider the mistake that you have just made."
Mr Proctor readily admitted his magazine’s latest mistake. "We missed a line out," he said. "There are two legs to the directions off the top of Ben Nevis. We missed out the line which included details of the first leg. It is incorrect and any inaccuracy in our routes is serious.
"We do say that our routes are meant to be used in conjunction with the appropriate maps. None of our walkers will be going out without those maps, and one look at that map will tell you that you need two bearings from the top of Ben Nevis, not one."