I answered a question on the TFF about this and wanted to share what has worked for me.

Go to Wal Mart and go back in the automotive section. There will be a plastic can full of black bungee cords/loops that have the black ball on the end. There are 15-20 in the can for less than $5.00. Anyway take them home and cut the ball off and they are the perfect length to replace the stock cords on your boat. These are a little thicker and you will need to save the hooks from the ones on your boat to use on these new ones. You access the tie off point beneath your gunnels through the rod lockers. Tie off to the mounting point and you are set. This is much cheaper than the factory ones and last longer. They also come in other colors if you want to spice it up. Carry one extra as a spare too.