Try Pamphlet No. 21 Regulations for Training with Armoured Fighting Vehicles, Infantry Weapon Systems and Pyrotechnics - Ch2 Section 2 and Section 3. It lists all the quals and should refer somewhere in there what the score is with CO's Auth. There is a sample Auth Certificate as an Annex as well I seem to remember.
I seem to remember that you could have personnel authorised by the CO to act as Safety Sups, as long as they were trained to do so by a suitably qual'd person. Haven't got a copy of Pam 21 to hand, but IIRC it's in the chapter dealing with qualifying courses etc.
Thanks Dygbi, found it, I went straight to Section 3 as i thought it would be there and didn't think to look in the General Section (Section 2)
Interestingly it doesn't state you have to hold any qual it simply states
0222. General. Where units have insufficient course qualified personnel to match their training needs COs are permitted to authorise unqualified personnel to supervise LFMT, LFGT, TLFTT or LFTT activities. Such authorisation is to be the result of a period of training using the Course Folder issued from either Inf TDT at HQ Inf or TDT at DRAC. Individuals are to have received sufficient instruction and have been formally tested so as to ensure that they are able to undertake their duties competently and in strict accordance with the appropriate regulations given in this pamphlet.
That's correct, you can get the CO to authorise anyone you (he/she) feels would be capable. I always used range Qual'd (B) to authorise to (E) and J/SNCOs who were not qualified to authorise for Safety Sup on static ranges. I also ran a 3 day course, day in the classroom and 2 days on ranges (inc dry trg), before I got the CO to sign off the authorisations. Touch wood, always worked out fine and I never had any issues safety wise with the range staff.