Very simply put, a "stroke" is somebody you don't want to dive with. It is somebody who will cause you problems, or not be any use to you if you have problems. Usually, this is a reflection of the attitude of a stroke, but that can be inherent in the personality of the individual, or others can teach it.
For instance, if somebody is taught that diving is an "every man for himself" sport, that you "can't help somebody deep," that "my gas is my gas," or "know when to leave your buddy," then that is somebody you do not want to be in the water with. Some people are natural strokes, but all too many are created. Unfortunately, people believe best what they hear first, and given the low-level food chain structure of dive instruction, most strokes are man-made, and are then hard to fix.
Obvious strokes are not so bad - you can see them and you know to avoid them. Frequently they will give it away with their choice of gear and gear configuration. If you see something that is a complete mess, makes no sense, is less than optimal, or is designed to accommodate some phobia while ignoring all else, you are dealing with a stroke. If the stroke is pontificating about how he can "handle" deep air diving, or obsessing about depth, or appears to be trying to compensate for internal fears, this is an obvious stroke and you merely avoid them.
The really insidious strokes are those who pretend to be squared away, but are in this game for all the wrong reasons. Usually they wish to prove something to themselves or others, or to overcome some internal fears. These tend to try to do things that they are not ready to do, and when something goes wrong, they flee for their lives.
Diving is not an intuitive thing. It is not a natural thing. Natural reactions of human beings on dry land do not work underwater. To be a good diver, you have to control your natural responses, and know that they can only hurt you, not help you. A stroke cannot do that. A stroke is driven by fear, ego, and self-concern.
By George Irvine
