When I did my deep dive to 300ft, I had a set-up of about 6 tanks, all 12ltrs. A double rig on the back and two doubles either side of me. So it was a simple matter of changing different air mixs to get to the wreck and the same when coming back and doing decompression stops. Sometimes if you judge it a bit wrong and need a little more time for decompression and you used more air than you planned (a little panic at 300ft can draw a hell of a lot of air), then the pony at 30ft allowed me to just chill out for ten minutes no worries.

How do you cope going over the wall? I did a dive off Madagascar, swam out over the wall, had a huge sense of vertige. I'm swimming along clear blue water, sand bottom below at 30-35m then nothing down to 2000m+ and inky blackness. I was stable just hanging there, weird feeling, couldn't wait to get back over that sand. Maybe I should do it a few more times eh?