[seafarer]

Not to mention that if you leave anything down long enough, you will find some form of marine growth that readily breaks it down - wood, leather, rubber, paint, glass - some animal, plant, or bacterial film will either erode it, decay it, eat it, or break it. The deeper it is, the slower that might go, but it will happen eventually. And like sand in the desert, no matter how well sealed you might think something is, ultimately, it's not.