Re: wooden oar
If you sand off the poly, you can use steam to bend it any way you like. Here is a youtube video showing someone doing it:
http://www.youtube.com/watch?v=OOIJXDZXB3g
You can alternatively just wet the wood slightly on the outside, then set the oar in the sun with the outside bend facing up. The rapid drying of the 'up' side will cause it to contract faster than the bottom side. Timing is important in the sun method, as too much time will just give a paddle bent the other way
Once the bend is gone, place the oar on a flat surface with some clamps holding it in place or something quite heavy on it. 24 hours later you can re-poly it and enjoy a nice straight paddle again.