Q: When is a Munro no longer a Munro? A: When it's a Corbett

Sgurr nan Ceannaichean downgraded from Munro status after falling 3ft short

Size, they say, isn't everything, but for the want of a few centimetres Sgurr nan Ceannaichean has been kicked out of the premier league of Scottish mountains.

For almost 30 years the mountain basked in its classification as a Munro, one of the 284 mountains in Scotland that were 3,000ft (914.4m) or higher.

It has now been reclassified as a mere Corbett, the mountains which can look impressive but, at just 2,500 to 2,999 feet, fall a little short of greatness.

Sgurr nan Ceannaichean, north of Glen Carron in Wester Ross, flirted with Munro status after the Ordinance Survey decided in 1981 that it reached 3,002ft (915m). It was reputed to be the smallest of all the Munros.

However, a recent re-measurement in July by the Munro Society using the latest in GPS survey tools showed that it was only 2,996.82ft high (913.42m) and it has been relegated to Corbett status.

Iain Robertson, of the Munro Society, said: "We use a GPS system which involves getting information from satellites. It is quite a protracted system. You have to spend up to two hours on top of a mountain which can, at times, be chilly but the results are very good."

Munros got their name from Sir Hugh Munro who was the first to identify all the Scottish mountains of 3,000ft or more and published a list of them – now known as Munro's Tables – in 1891.

The list spawned Munro bagging, a popular pastime among walkers and climbers in which they endeavour to climb all of the Munros. When they have a full set of Munros to their name they are eligible to join the Munro Society, which was founded seven years ago.

The new measurement for Sgurr nan Ceannaichean, which gets its name from the Gaelic description "Peak of the Pedlars", has been accepted as accurate by the Ordinance Survey.

Three other peaks were measured during the summer and the results showed that two of them, Beinn Teallach and Ben Vane, should retain Munro status while the third, Sgurr a'Choire-bheithe, should retain its classification as one of the 220 Corbetts.

All of the peaks that were assessed this year were close to the 3,000ft height. Other mountains close to the Munro qualification are expected to undergo the verification process next year.

Sgurr nan Ceannaichean's nemesis came in the form of "Clem" Clements, a member of the Munro Society who decided to celebrate his 40th anniversary of reaching all the Munro peaks by paying for the fresh measurement.

Getting mountains reassessed for height is considered to be in the tradition of Sir Hugh who was anxious measurements should be as accurate as possible. He commonly carried an aneroid barometer to measure the heights of mountains in the days when only a handful were recorded in detail.

More than 4,000 people are members of the Munro Society.