We don't have synonyms for sea silk yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are seasick, sea sick and sea mile.
(n) :
An extremely fine, rare and valuable fabric produced from the long silky filaments or byssus excreted by several molluscs (particularly Pinna nobilis, rough penshell) by which they attach themselves to the sea bed.
(n) :
An extremely fine, rare and valuable fabric produced from the long silky filaments or byssus excreted by several molluscs (particularly Pinna nobilis, rough penshell) by which they attach themselves to the sea bed.