Rudder bands

Ancient ships had two great broad-bladed oars for rudders. These, when not in use, were lifted out of the water and bound or tied up. When required for use, these bands were unloosed and the rudders allowed to drop into the water (Acts 27:40).

Noah Webster's New International Dictionary of the English Language

1. (n.) A riddle or sieve.

2. (n.) The mechanical appliance by means of which a vessel is guided or steered when in motion. It is a broad and flat blade made of wood or iron, with a long shank, and is fastened in an upright position, usually by one edge, to the sternpost of the vessel in such a way that it can be turned from side to side in the water by means of a tiller, wheel, or other attachment.

3. (n.) Fig.: That which resembles a rudder as a guide or governor; that which guides or governs the course.