I enjoyed this meditative sonnet. So many unanswered questions.
The DG has rightly pointed out the nautical allusions, and, if I may go further, the whole brings to mind the paradox of the ship of Theseus, a theme very dear to my own heart.
Also the idea of what is true or false is portrayed in the real, versus the synthetic, corks.
The double meaning of craft is finely placed.
I assume the title is hyperbolic
!
I like the ambiguity of the final line.