Section 83.32 - Definitions (Rule 32)(a) The word whistle means any sound signaling appliance capable of producing the prescribed blasts and which complies with specifications in Annex III to these Rules (33 CFR part 86).(b) The term short blast means a blast of about 1 second's duration.(c) The term prolonged blast means a blast of from 4 to 6 seconds' duration.