I'm not a yeller. Double handed I don't yell if something is done incorrectly, if and when I yell it is to make sure that I am 100% understood, and there is no question as what needs to be done. Like: "BLOW THE JIB!!!!!!!!!!!!!" when a pitchpole looks inevitable when its howling, or some other unavoidable action needs to take place to save us from certain peril and it needs to be done now.