VLF means Really Minimal Frequency and is the same technology Employed in detectors crafted for cash, jewelry, and relics. VLF detectors broadcast at frequencies calculated in kilohertz starting from three kHz to 70 kHz. Here's 5 main reasons why you could possibly go with a VLF more than a PI https://divekeeper.com/forums/discussion/technical-diving/gold-detector-thrills-and-spills