It beeps when you first attach the DESS key, but it will also beep a short time after you shutoff the boat if you leave the key in. Often times we'll shut off the boat somewhere if the kids want to jump in the water or if we want to stop to have lunch. That beeping is actually much worse than the initial plug-in beep. Sure, we could unplug it altogether, but the tape "fix" is nice because our ears will never get caught offguard. ☺
What I've found is the most annoying about the beep is when other nearby Sea-Doo PWCs beep, for example, when we're all onshore. That leaves me wondering if I left the key in. It would be a nice little feature to be able to customize the beep--at least from some predefined ones.