DB well said, I think you and I are on the same wavelength! I am amazed that some operators are using a fixed height above the sea, thus making every offshore approach look different! What is the sense in that?
To be precise, Bristow does have a minimum of 300' above the sea, this was to avoid being very low before starting the approach when landing on a deck with a deck height below 100', but there aren't too many of them.
We all fly the same types but it never fails to amaze me the differences in operating procedures between the 3 companies.