What's the noun for tillowing? Here's the word you're looking for.
tiller
(archery) The stock; a beam on a crossbow carved to fit the arrow, or the point of balance in a longbow.
(nautical) A bar of iron or wood connected with the rudderhead and leadline, usually forward, in which the rudder is moved as desired by the tiller (FM 55-501).
(nautical) The handle of the rudder which the helmsman holds to steer the boat, a piece of wood or metal extending forward from the rudder over or through the transom. Generally attached at the top of the rudder.