The Couloir is a sought after descent, despite being short in length. A significant feature of the descent is dealing with the Great Slab - a large area of granite that is often the scene of some specatular full depth avalanches in the spring. Glide cracks often appear well in advance of this, and can be a hazard in themselves.
The gully doesn't actually start from the corrie rim, but 5m below it from a small saddle just to the West of the summit of Cairn Lochan. This point usually offers a break in the cornice. The short slope to the saddle is at an easier angle than the gully itself, but can feel exposed with the chasm of the Left Branch of Y-Gully on skiers left. Despite being short, the gully is quite steep. In good conditions, there should be plenty of room to manouver, but when relatively lean, it will be a lot narrower.
Once out of the gully, and you are in any way concerned about the snow on the Great Slab, stay hard right, almost to below The Vent, and head down to the lochan from there.
Approximate Start Height: 1200m
Approximate Descent: 270m
General Aspect: Northeast
Climbing Grade: I
Notes: The gully is steep for Grade I, but short.