This detector is for my brother I'm purchasing it for his birthday so I'm trying to get it right . It's between the AT Max and the amphibio multi...My question... If you discriminate iron will you still hear it come through the detector... I've read a post saying you can discriminate iron out but you won't see it on the screen but you will still hear it come through the detector is this the case.....Do you guys think it is suitable for occasional Beach in saltwater..