Mark, I received your email> I have not had any reports of the weighted tubing being severed.We had a Parks and Rec Dept in Washington State that had issues on some fountain power cable being chewed by beavers but the weighted tubing in the same water was untouched.They purchased weighted tubing to put the power lines in and stated that did the job for them.How much tubing is exposed onshore and would it be practical to slide it into metal electrical conduit or as Eric suggests try the tin foil route.Not sure if they will go after the tubing "in" the water or not. Post some pics if you find time.Ted