In my latest G.P,A,A, mag, a guy wrote a very nice story about Swinging on the Ocean Beach of San Diego. In it, it's got a formula, Less Friction + Shrinkage + Rings in the wet sand, which equates to a very happy treasure hunter. You could add lubrication to this formula, sun tan cream.
But what's more important is his style of detecting As he is walking along the beach he does a S pattern, which I think means a zig -zang. Now here's the important bit. He's looking for a pattern in the beach where he finds the targets. Are they in a line or in one spot ? This could save a lot of time searching and more targets.
Happy Hunting