to reef the paddles

from The Collaborative International Dictionary of English v.0.48

Reef \Reef\, v. t. [imp. & p. p. {Reefed} (r[=e]ft); p. pr. &
   vb. n. {Reefing}.] (Naut.)
   To reduce the extent of (as a sail) by rolling or folding a
   certain portion of it and making it fast to the yard or spar.
   --Totten.
   [1913 Webster]

   {To reef the paddles}, to move the floats of a paddle wheel
      toward its center so that they will not dip so deeply.
      [1913 Webster]