The surveyors on Sail Chalmadale

Baggers, get your boots on! There’s a new marilyn to be conquered.

Sail Chalmadale, a modest hill on the western side of the isle of Arran, has been elevated to the list following a survey conducted by the trio of latter-day Sir George Everests who recently managed to get Mynydd Graig Goch confirmed as a mountain.

Alan Dawson, John Barnard and Graham Jackson have established the 480m (1,575ft) peak overlooking Glen Iorsa has the required drop of more than 150m to qualify as a marilyn. The exact prominence, surveyed by the three men, is 150.5m.

According to the trio, the former ‘sub-marilyn’ has been a favourite candidate for promotion for years. Another Arran hill, Beinn Tarsuinn, was surveyed by them, but failed the test with a drop of only 148.5m.

There are now 1,555 marilyns on the list, and an extra hill to climb for all those who thought they had them all in the bag.

The men, who have GPS-based, hand-held surveying equipment for maximum accuracy, hope to measure more sub-marilyns in the near future.

But, as The Angry Corrie editor Dave Hewitt, points out, there  really ought to be a survey of hills which only just qualify for status as marilyns, munros or whatever other standing they have, in case they are not as high or as prominent.

The survey in progress, with the measuring equipment and antenna on the tripod, with small, 'conventional' GPS units on the ground

This would be, says Dave, a more statistically pure approach.

Still, for those needing to complete their updated list, the hill can be found 4km inland from Arran’s west coast, near Dougarie. Book your ferry tickets to Lochranza or Brodick now.

• John Barnard, one of the men who carried out the survey asked us to clarify the process: “We do have hand-held GPS units like the Garmin/Magellan units but we don’t use them for this sort of measurement. 

“However the accurate equipment is NOT hand-held and is altogether in a different ‘ball park’ and costs thousands of pounds. There is also a question of post-processing the data using corrections from the OS active base stations that hand-held units cannot do. It is tha latter that gives the great accuracy of these measurements.”

Sorry if we caused any confusion. See picture right for an idea of the gear used - Editor

See also

Marilyns, munros and how to make a mountain out of a moel hill