| Neil You may have left it a bit late. By standard I assume you mean standard dress as opposed to the modern “Tupperware” hats. I did my course in 1979 and it must have been one of the last training courses on the standard copper 6 and 12 bolt, The MoD dockyard divers and Manchester Ship canal divers may have used them later but not much. I think the lack of a bailout got them NRB. The MoD had a replacement helmet called the Windak about 1980 never went far I think they were just prototypes. I suppose the Swindel, Advanced 2000, Beckman and the MK 12 don’t count, Most went on to the Aquadyne and the UWI air hat. I guess most 12 bolts helmets are in theme pubs now. iain |