Saege states that you are able to wear this necklace everywhere, swimming, day and night. With no issues. They also state as it is gold plated, the gold colour will never vanish.
I have had my necklace for 4 months - worn on two short city breaks - nothing else - and yet, the gold from the chain itself has vanished. I haven’t worn this to swim in either, maybe just sweat as I have visited hot countries, but it has also left a quite distinguished green ring around my neck.