I built my own noisemaker after catching a guy in the act of stealing my kayak late one night in Miami. My kayak wasn't cable locked at the time but on front porch. I heard the sound of it being slowly slid across concrete. I quietly got up, went to door leading out to porch and turned on light and burst out screaming profanities at him. He left on bicycle, he had a lookout on bicycle, and had transport guy in a vehicle in the alley.
Bought a cable lock the next day that I secured around porch column to keep the amateurs from snatching and made a noisemaker to hopefully scare off the professionals or wake me up. The noise maker was simply hidden fishing line under kayak that would trip a bucket filled with some empty cans. Hard decision whether to make the line short and trip bucket as soon as it was moved or give it 20 or 30 yards of free line before the 50# braid would have given them a running start and maybe double the pleasure, so I had both.
Never had it tripped but have often thought of something that I could set off inside kayak to make racket or flashing light.
A good rule of angling philosphy is not to interfere with another fisherman's ways of being happy, unless you want to be hated.
Zane Grey, Tales of Fishes, 1919https://vimeo.com/73372194