true that.

OED2 has it like this:
sea-change, a change wrought by the sea; now freq. transf. with or without allusion to Shakespeare's use (quot. 1610), an alteration or metamorphosis, a radical change

1610 SHAKES. Temp. I. ii. 400 Nothing of him that doth fade, But doth suffer a *Sea-change Into something rich, & strange. 1917 E. POUND Lustra 193 Full many a fathomed sea~change in the eyes That sought with him the salt sea victories. 1923 J. M. MURRY Pencillings 164 The characters which have suffered this sea-change, ‘of whose bones are coral made’, are the only unpleasant characters we remember. 1948 A. C. BAUGH Lit. Hist. England II. IX. 173 An interesting paper suggesting that romance is transplanted epic, which has undergone a kind of sea-change in the passage. 1974 R. HELMS Tolkien's World ii. 32 Even before The Hobbit was published he was at work on its sequel, a work in which Middle-earth has undergone a wondrous sea change. 1976 Listener 8 Apr. 450/3 The Messianic vision..has undergone some strange sea~changes outside Judaism. 1977 ‘E. CRISPIN’ Glimpses of Moon vii. 117 He..could, moreover..bring about a sea~change in the image of even the most bumbling police officers going about their duties, so that they emerged as prodigies of intelligence, zeal and kindness. [EA]