The UK offshore wages are higher than onshore because no one in their right mind would fly the dullest rotary job available in the crappiest weather, wearing extremely uncomfortable attire for hours on end(and given the 14lb life jacket, potentially spine and neck damaging) dealing with all of the corporate b.s. and always being asked to be "flexible" for onshore wages? Offshore would have no one left to fly if they paid the same?
Onshore wages are now creeping up, and as Helimutt says, we are not fixed wing and there is a demand for qualified pilots. Any offshore redundancies will most likely be voluntary and the whole of the uk has a really ageing pilot fleet. No one is coming up through flight school and military leavers are few and far between...
There are jobs out there, and of the 14 tupe'd pilots from Bristow to Babcock 7 of them have already taken jobs elsewhere ( I'll leave that open for you all to ponder why)
B.