33 C.F.R. § 86.11 Fitting of more than one whistle.
Title 33 - Navigation and Navigable Waters
If whistles are fitted at a distance apart of more than 100 meters, they shall not be sounded simultaneously.
Title 33: Navigation and Navigable Waters
PART 86—ANNEX III: TECHNICAL DETAILS OF SOUND SIGNAL APPLIANCES
Subpart A—Whistles
§ 86.11 Fitting of more than one whistle.
