Does a weight of a diver determine her air intake? Or do smokers use more air? I've dived with both an overweight diver and a smoker, but they seems to be using less air than me. I dont smoke and not overweight. This is irritating.
I'm overweight.... so, proper breathing techique seems to be your issue.
Btw... in most cases (when we breath normally), Male tends to use up air faster than Female, Overweight divers tends to use up air faster than normal weight divers.... not too sure about smokers, as my smoking dive buddies are very skinny
So... proper breathing techique will help alot.