The silver, being the anchor of every character's dream-ideal, now plays that
role literally: Decoud clings to it as a physical relief from the unpredictable
buffetings of the darkness. The terror of being "flung about" by the
mysteries of the unknown makes one "instinctively" cling to any physical
object, i.e., any dream-ideal, any society, at any price. Hirsch does exactly
the same thing with the steamer's anchor below, with terrible consequences for
him.