Chinook HC2/2A? "HG"

I have taken some photographs of an RAF Chinook marked “HG”. Can anyone give me a bit more information, just for my website.

I’m not even sure if it’s an HC2 or HC2A (HC3???? – very unlikely, but possible as they are in very restricted use, I believe – but with the current troubles, the force is bound to be a bit slim at home).

It was participating in exercises near my home, with RN Marines (I think).

You can see the pictures by Clicking Here

Thanks.