If you want to go offshore as an ROV technician, then I’d suggest that you go for the HNC in electronic engineering; I believe it is still the case that it is the minimum requirement (apart from a tradesman’s apprenticeship) for most of the aberdeen and north east england operators. I think it can be done in a year whereas the others take 4?
I’d have a look at CTC Marine Projects, MODUS International or Global Industries web-sites – they are right on your doorstep – not sure if they are recruiting at the moment?
If however you want to go for a more engineering role and get into operations design/managing projects offshore, then I’d aim higher in terms of education level; most of the technip guys I’ve worked with seem to be chartered engineers. I don’t recall any of them having the subsea engineering degree though… I think it’s a new degree.
Good luck.