I should update... I have actually worked out how to get it to run.. the trick is the frequency. My procedure is. Get to the salt water. Put the max in all metal and run threshold. Ground balance but then hold the coil about and inch off the wet... Turn up the sensitivity till it's unstable then flick through the 4 frequencies,,,,, one will be way smoother... At this point I back off the sensitivity 1 bar. Then run the zero mode but disk out to about 30,,,,, less if you can,,, depends on the beach. It works a treat and is as good as any other detector I've used. I'm happy anyway.. I think Garrett made a huge marketing blunder keeping the Max in the same chassis as the older At series. It's being overlooked but it's a great unit... When you select beach mode on the Nox,,, it's pretty much doing the above... The Garrett is just a manual machine. Once I realised this the beaches have opened up for me.
Cheers
Brian