I don't know whether this is relevant because we do not know what they where attempting to do towards the later part of the flight. However, Weather Radar can be tricky to set up correctly to pick up obstacles on the surface of the sea, especially if a turn is involved at sufficient height that when the turn is complete the radar sweep is now looking over the top of the obstacles. Or in other words, the descent angle from the helicopter is too steep for the radar to sweep the flight trajectory.
I managed to "miss" the Miller Platform doing just this positioning for an ARA to the BRAE A. A knee trembler when I saw the Miller go by my window not to far below me.
I struggle to accept though that with a well trained crew like SAR, three of them navigating and looking at screens, in a high workload flight phase like the final positioning and descent, that they could end up making the same mistake I did.
If I was tasked with that let-down I would have used the BLACKROCK island as well for my IP and transition onward from there to the bay, but then again I am not sure how tight you can make a let down pattern in the BLACK SOD bay and I am not SAR.
Maybe Crab can let us know what the "standard" approach (excuse the pun) to a problem like this let-down in the bay would normally be for a SAR crew.
It seems very reasonable to me what they did in terms of the flight path, and maybe the close proximity of the wreckage to the island could just be a misleading red herring, in that they were doing a solid procedure and something went wrong as the got close to the island.
As an Aviator who has spent a long time over the sea, bored, lonely and eating mainly crap meals, I would not criticise the SAR Community for anything as they have always been my last hope should something go tits up with me chopper.!!
DB