The Collaborative International Dictionary of English v.0.48:

Cockle \Coc"kle\, v. t. [imp. & p. p. Cockled; p. pr. & vb. n.
   Cockling.] [Of uncertian origin.]
   To cause to contract into wrinkles or ridges, as some kinds
   of cloth after a wetting.
   [1913 Webster]

   Cockling sea, waves dashing against each other with a short
      and quick motion. --Ham. Nav. Encyc.
      [1913 Webster]