This section is from the book "The Boy Mechanic Vol. 2 1000 Things for Boys to Do", by Popular Mechanics Co.. Also available from Amazon: The Boy Mechanic, Vol2: 1000 Things for Boys to Do.
The rudder of a sailing dory or row-boat often comes off in rough water, and in order to keep it in place and yet have it easily detachable at will, the following method is useful: Procure a 10-in. iength of soft-iron rod and bend one end of it into a loop large enough to fit around the rudder pin after the latter is inserted in the eyelet. Insert screws at A, B and C, letting them project about 1/2 in. from the surface. Bend the rod at D and A in the shape shown, and with a little adjustment it will easily snap into position. It will prevent the rudder from riding up out of the eyelets, but can be detached instantly. The device should be applied to the upper pin so as to be within easy reach. - Contributed by B. A. Thresher, Lakeville, connecticut.
Ill: The Loop on the Iron Rod Holds the Pin of the Rudder in the Eye