On DIR-F we had rescuing toxing and unconscious divers shown to us but we didn't practise it... On Tech 1 we did as And has described... swimimming the diver up from behind is excellent, twas like riding a scooter so it was...
I did my CPR and Oxygen administration with Andy Hayhurst (Dalesdivers) very good and very cheap.. I'd recommend this class to anyone.