Devil49,
That is an excellent paragraph for Part 135 operators. It is an operating rule for those 135 operations only, and has no force for Part 91 or 127 operations. It is similar to the Part 121 rules with increased VFR takeoff requirements (2000 feet), in that it raises the basic FAR level of safety for commercial passenger carrying operations.
However, to support your position, I know of no offshore operation flown under Part 91, they are all Part 135, I believe.