Just to report back.
Didn't do Am Buachaille as the thought of the swim for Josh and me without a wetsuit was too much!
Did do Stoer. We threw Flo in the water with a swimming costume on. Sea was okay but not flat. The far side belay was all in place with an obvious powerpoint of two lockers for her to clip an alpine butterfly in the mid point of the rope (old 8.5mm dynamic). I tensioned both strands of the rope using a micro trax on each strand to the power point my side. This was formed of a small blue DB C4 cam, the only piece under tension, backed up by 2 bomber wires. The use of two strands ensured much less sag.
The descent ab dumps one right on the stack-side belay. Two of us went back over the fixed lines. The third clipped himself to the alpine butterfly, took in all the slack in the rap lines and we hauled him across with him still hanging from the rap lines. This seemed an ideal way of doing it
The idea of the swimmer swimming back to get dry would be a good one in calm seas. Flo was worried about being swept out without a safety line.
The route was excellent. Very solid rock. Not really possible in two pitches due to drag. Sun setting on the summit.
Did Hoy the day before - even better. Then Agag's in Glen Coe the next day; then the classic and hard rock ticks on Arran the following day.
Great trip. Thanks for your help.
Post edited at 14:28