[Garf]

I'm going to give this one the benefit of the doubt even though it's set off my troll detector...

The leopoldville is in 57 metres and the Rotoura is in 60 metres. Let's not piss about; unless you're one of those superman-like characters who claims they don't suffer from narcosis, you'd be narked off your tits on air, and you might as well be diving the Stangarth for all you'd remember about the wreck. It's also a waste of time doing dives like that in 12's as you'd only have 15-20 mins on the wreck. There are other options, such as bigger backgas cylinders or bottom stages, but if you've only just passed a nitrox course, and you found the nitrox course hard, then you're realistically not ready for the dives you are talking about. Get some experience in shallower wrecks first and then set those deeper wrecks as targets for a future date. They will still be there.