If Epd is larger, then the compressor will be spinning faster than the manufacturer’s maximum specified RPM and might destroy itself. If this happens, then the compressor again might not produce enough air to support a diver. Neither is a desired outcome.

We’ve had two trips to the deserts of Nevada and explored mines and mill sites, hiked miles of ravines in California, and swung our detector coils over thousands of square yards of bedrock.

The old timers typically washed these areas down to bedrock, and some areas appear terraced. I would imagine this is because these hydraulic mines were generally where the miners found old Tertiary river channels on the sides of mountains that were gold-bearing.