An interesting cloud formation I spotted from the track from Machir Bay to Kilchiaran. Reminds me of waves breaking in the sea, seen from the side.
Update: As per the comment below, I now believe this is an example of Kelvin–Helmholtz waves/instability, a relatively rare phenomenon.
Interesting! I think this might be what they are:
http://www.dailymail.co.uk/news/article-2416913/Unusual-Kelvin-Helmholtz-clouds-stuns-locals-watch-surfers-Seaburn-Beach.html
Maybe worth sending to the Cloud Appreciation Society!!
Oh, thanks Jo, had no idea what might have been behind it and that there is even a name for it. But the description sounds about right, they were only there for a short time.