Rubble ridges, which have been built parallel to the shore, help retain some sand without fully stopping the natural flow in the lake.

Only 15% of the bottom of Lake Michigan has really been mapped, and that's comparable to our nation's coasts. So there's really a need to map these systems out. That is one outcome of this.

Researchers discover site of 1893 schooner wreck in Lake Michigan in just 50 feet of water ... But a new discovery is putting another ship – the Margaret A. Muir – on the map.