I used cotter pins when I had a P16 because there isn't much room to insert a split ring. A cotter pin would be fine for your use. I take my rudders off when I trailer the boat to races or when there is unusually nasty weather on the way when my boat is on the beach. I really don't like this type of rudder system. I've learned how to tweak it after all these years but would prefer any of the other systems available.