That looks like Rainbow number 3 which we escaped just about that time this morning. Rainbow number 1 soaked us as did number 2. I am now frightened of rainbows.
I was going to put the pic below in the the "Well blow me down" thread, because, well blow me down, I've never seen a horizontal rainbow before. But since Perikles included rainbows here I am putting it here. This picture was taken this morning from near the base of the mountain above, looking to the north toward Los Gigantes. I know the colours didn't come out so well but that is actually a horizontal rainbow!