ARM 12.11.320. SOUND PRODUCING DEVICES ON MOTORBOATS

(1) Motorboats shall have efficient sound producing devices as follows: (a) less than 16 feet in length - none; (b) 16 feet to less than 26 feet in length - one hand, mouth, or power-operated whistle, or horn, audible at least one-half mile; (c) 26 feet to not more than 65 feet in length - one bell which when struck produces a clear, bell-like tone and one hand or power-operated whistle, or horn, audible at least one mile.