You can see the white froth of the waves on a rough northern shore, looking like a white grin along a curved beach.

‘… a grin of surf lined the northern shores.’

See also the quote rich mosaic review of this magnificent, entrancing book: a love letter to islands and a paean to the sea. 

Source: Adam Nicolson, Sea Room: An Island Life (London: Harper Collins, 2013 (2002)), p. 211