I made some out of bicycle inner tubes that work perfectly. Directions per drip ring. Cut the inner tube into a 4? inch length. Cut another peice 6ish long and slice it open until you have a flat peice of rubber. Make the flat peice square and cut a small hole in the center. Now the hard part. Strech the 4? inch lenght over the end of you paddle to the loom. Strech the flat peice with the hole over the blade as well. If you made the hole too small, it will rip, to large and it doesn't help you. Strech the flap up so there is a small flange facing the center. Fold the 4? inch peice over on itself and cover the flange part of the flap. Sounds simple, but its a serious pain streching the tubes over the blades.
http://s2.photobucket.com/albums/y23/tbdesigns/paddleboard/?action=view¤t=dripring2_1_1.jpg
http://s2.photobucket.com/albums/y23/tbdesigns/paddleboard/?action=view¤t=dripring1_2_1.jpg
Scott