The depth sounder
I had on an a fishing dinghy
years ago used to get lines of interference
on it whenever Dolphins were around.
Dolphins would often show up at the bait ground off the town of 1770 in Queensland
. Always knew when they were coming by the sounder getting funky. Happened too many times to just be coincidence and never saw the same interference
when there were no Dolphins about.
Have never seen it on any other sounder or location but that one. Wondered if they were hearing the sounder transmissions and were trying to "talk" back to it. Anyone else seen similar?