In reply to dan wisey:
I'll support Tobe's reply too. My step son is a rope access technician - I'm not sure of the grade.. He's a metalwork & welding specialist. He can make, fix or repair anything you wish out of metal and weld/braze anything, and that is what he mostly does at hight ,
My grandson is a saturation diver and can, if he wishes work anywhere he chooses. He is a an engineering specialist. He could probably repair an undersea engine or pump but also things I don't understand properly to do with testing and so on.
When I've joked about joining them and paying a fortune for their tickets and updates every year or so, that even if I qualified, theyve both asked me; "what could you actually do when you got to the workplace?" = and of course my answer is very little!
Yes there are rope access technicians who have no specialised skill and I know there are divers of some description who have no special skill and you can probably go that route. Whatever you do in terms of diving, I hope you achieve your aim but it isn't easy. Good Luck.