40.1 Basic Rule When rule 40.1 is made applicable by rule 40.2, each competitor shall wear a personal flotation device except briefly while changing or adjusting clothing or personal equipment. Wet suits and dry suits are not personal flotation devices. 40.2 When Rule 40.1 Applies Rule 40.1 applies if flag y was displayed afloat with one sound before or with the warning singal, while racing in that race; or flag y was displayed ashore with one sound, at all times while afloat that day. a rule in the class rules, notice of race or sailing instructions states that it applies.