Yeah, some beaches have such hot ground/black sand, that at minimum pulse delay you will get constant falsing. Turning up the pulse delay makes the detector sample the ground signal a few uS later, and makes it run more stable. When I owned the Sand Shark, there were a few of my beaches that have super hot ground, and the SS would see the ground as one big iron signal, and without a pulse delay control to tweak, I couldn't hunt those beaches at all. The PI I use now has ground balancing, so I can leave the pulse delay at minimum always, but with a PI without ground balancing, pulse delay is a must, IMO.