So how would O&G or corporate crews conduct an IMC letdown to Blacksod at night with a 300' cloudbase?
I fly an S92 for O&G. We would not have been permitted to fly an IMC letdown or any type of IAP to Black sod or Black Rock. In order to fly any type of offshore procedure (such as HEDA, OSAP, ARA) we are required to be at least 5nm offshore from any land. We could base a procedure 5nm offshore from Black Rock, but would then be required to meet VFR minimums in VMC towards Black Sod for a landing. While we could have descended to 200', at the end of the IAP we then be required to proceed under visual conditions. Problem would have been that with a 300 OVC at night, we would not have had legal VFR minimums or legal VMC conditions and so would have had to do a missed approach. We are not SAR, so this reflects what an O&G aircraft would do.