I tried this once off the Challenge. I agree with Pete. thankfully, I too realised the error of my ways!

Have just noticed your query about the N Morar Ridge. I took this route in 2016. Like you I did research into FWA's. Certainly, heed all recommendations to avoid any route along the north shore of the loch. The ridge top itself is rough and rocky and quite slow going. The map cannot do justice to the ruggedness of the terrain. In good weather, which luckily we had for the first few days of the 2016 event, it is exhilarating and gives magnificent views over Loch Nevis and Loch Morar. The Coire Dubh area provided a good camp spot the first night out. My abiding memory of the ridge was what a wonderful place to be in good weather, but what an awful place it would be in foul weather. I resolved never to come here in bad weather! This just confirmed my vetter's advice which was that unless you are sure of two days of at least reasonable weather after leaving Morar, the best and safest course was to avoid the N Morar Ridge altogether. Once you get to Tarbert you are committed.I know some people have used a route along the S shore of Loch Nevis via Kylesmorar to Finiskaig and then reach Glen Dessary that way, but not having done that route myself I cannot comment on its suitability. Of course once you get on to the N Morar ridge you have to get down again at some stage! As my aim was to get to Gleann an Lochain Eanaiche, I started the descent just after Sgurr na ba Ruadhe and reached the floor of the glen about a half km upstream from Kinloch Morar. As the map shows this is unrelentingly steep but at least it's mostly grassy at this point. There are rocky areas but they can be avoided. The path alongside Loch Eanachie is delightful, although I confess I was a bit too knackered by that time to fully appreciate it! The second day out was by far the most strenuous of my 2016 crossing - it was also the shortest at just under 9 miles. By the way, my FWA had been to take the bus or train from Morar to Lochailort on the morning of the start and sign out from there instead.