Walter
Firstly, yes I was referring to that islander ambulance. You're correct in your comments. Probably he overbanked it in the proc turn while looking 'up' for some sort of reference on the ground.
I'm not as well equipped to answer your second query. I suspect that the Chinook crew would have been visual with the surface more or less throughout. With the Mull shrouded in cloud, and it's often really just the actual high ground that's covered, their forward (and downward) vis might only have reduced when they were very near. Plainly they realised they were in danger and started a pull up. Maybe they could see from looking down at the sea state, that they were very near to coasting in?
You mention some sort of let down to land. I have no idea how that could be done except perhaps with the weather radar (does a Chinook even have wx radar?). One thing is for sure. Any approach to land here, in this wx, would be fraught. There is only the MAC to give you a PL but no DME.
I would be going really slowly, but these guys were seen by a yachtsman and going at a fair clip.
I'll bet they could see nothing of the high ground at all. It's not a question of 'blurring' surface features. You would see sweet FA forward but if low enough maybe you'd see the beach or waves and realise where you were- then time for full power and a big pull up
It's just a shame that the MAC had no DME.
Tucumseh.
I didn't know that. I based my comment on the fact that they were plainly climbing hard. Surely if it could climb, it could also have turned. Most FMS will start a turn before the turning point. How much before naturally depends on how big the change of track is.