I use a feeder for deer in NW Wisconsin. On my first try a bear made quick work of it, they can bite right through a thick plastic bucket. What I did was suspend it with a rope between two trees, out of the bear's reach.

If you have a spot that's good for feeding between two trees on the shoreline you could suspend a rope over the water on a pully for refilling, that'll keep bears out until they learn to fly. Then I think we're all done for.