I thought about taping a piece of magnet to the outside of the water. However, all the magnets I have were being used for something else. So I went to HFT and bought 150 lb. Pull Retrieving Magnet for $10. Let me tell ya, 150 lb. pull is a lot of magnetism!! 
150 lb. pull is a major overkill, but it works. Also, I need it for something else, too!

150 lb. pull is a major overkill, but it works. Also, I need it for something else, too!