It’s a matter of perspective.
In today’s fast-paced world, where everything is instantaneous, this iron chain will take ages to rust. The saltwater washing in and out with the tide will take weeks … maybe months … to turn each ferric atom into a small speck of red dust.
But in the big scheme of things, it will be evanescent. At the universal level, it will be zapped away in a relative instant. A fleeting moment in the annals of existence.