I have done the Blue Hole at Gozo on a single 15ltr, down to 47m. OK so was a language issue I thought the Italians meant 40m. The slow ascent up the wall was pleasant enough. So a bounce dive of sorts. This was fab viz, visual references and minimal narcosis effects (BTW I think I know my various states of narcosis, done deep air in the UK and trimix)
For the UK never.
Blue, warm water. Maybe
