On my last trip south a pal-o-mine came along. He's a weed-head to say the least.This dude was firing up in the parking lot at the airport, in the rental car on the way to the motel and his room smelled like a pot house. We dove like three dives a day and he was smoking in the mornings before the dives and at night. Not being a smoker or drinker myself, I just wondered how this would affect a person's ability to reason in case of an emergency and if it would affect one's lung capacity. I noticed that he used a lot of air on these dives. Anyone have any experience with this?