This is one of those threads where I find the drama more interesting than the subject. And it seems to me that most people are missing the real point. It's not so much about getting high as it is about the flawed buddy system. OK, it is a little about getting high because the OP asked about how impaired someone gets, and is it bad enough to worry about.
But think about it. He didn't know she was a smokitadopita until she told him. He couldn't tell by her actions. Then she admits getting high and all of a sudden he starts worrying. Well, that's too late! It doesn't matter if they're high, drunk, on meds, or just plain stupid, if you are depending on somebody you don't know to be your backup in a life-threatening situation, well, is that really the best choice?
Rick brought up stoners trusting criminal dope dealers not to poison them. But I don't think most people realize how often we all do that kind of thing. Do you know everything about the food you eat? Do you know everything you ought to know about the compressor that compressed the air in your cylinder? We all walk around in this warm, fuzzy cloud of trust, which is usually OK. I mean, I'd rather live on a positive vibe than a negative, paranoid one. But I also make an effort to check things out.
"I've read the label on this can of beans, so now I know absolutely, without a doubt, every last detail about what's on that label."
The OP asked if getting high impairs you enough that he should worry about it, and should he start asking people if they toke. I'd say, first, you should assess your reliance on the buddy system. Getting high is just one of many things that can make someone a bad buddy. Are you going to ask them all that? How long would that take? Second, if you cannot tell if someone is high, I mean, what do you think is going to happen? Everything is so normal you can't even tell they're high and then all of a sudden they start wigging out? Well, I guess for someone with no experience, and no idea what it's like to be stoned, that's not so unreasonable a question. But my answer is I don't think being a little high is any more of an impairment than a lot of other things people do before a dive. That's not an endorsement, just an answer to the OP's question about how much he should worry about it.
I'm still a relatively new diver, but one of my goals is to increase my experience, skills, training, fitness, and gear so that I am as prepared as anybody can be to go diving solo. Not that I would, but the point is that the only way the buddy system works is if the buddies are a true team, and for most of us that never happens.
