As usual, I agree with Dew. In terms of foil, its the price of small gold sensitivity range. Now as to gold going to the surf area...
In my experience and understanding, gold objects (and rings the most) are the least likely objects to move laterally, but like to move vertically until density stops its progress. If the surrounding medium moves it will move, but the medium will lose density and the gold will seek an even lower resting place as it travels. The numerous variables of wave action and medium composition acting with the constant of gravity make even generalizations hard to predict. I'd welcome criticism on my theory formed over many thousands of hours of musing while waiting for my headphones to make my day.