fnfalman
Contributor
@fnfalman: I understand your point...but I think the decision to wave goodbye to an insta-buddy deviating from the dive plan might not always be so clear-cut. For the sake of furthering the discussion, would your response change if you knew that your buddy did not willfully intend to descend to a depth of 150+ fsw? For example, imagine a scenario in which a diver has his/her LP inflater hose pop off of the BCD power inflater. With equipment malfunctions of this nature, I've seen newbie divers "freeze" (no kicking, no actions to rectify the situation). At that point, an attentive buddy within arm's reach would be in a position to intercede. Passive panic can certainly manifest like this. If the dive plan called for an operating depth of 100 fsw or so, it's certainly possible that narcosis played a role in the buddy going substantially deeper.
Just something for all of us to think about...
In your case, the buddy should stop the diver from descending further. If it's equipment failure, then assist the buddy. But if after hand signaling and nothing is wrong with the equipment yet the other diver insisted on going deeper than planned even though I signaled that I won't agree to further descension and that buddy kept on going? Then have fun! I'll be where I'm at.