The two photographs below I took may not exactly be anything to get excited about. However, this was a new observation for me. I had the pleasure of doing some field time with a few other folks versus my usual solo trips and Elizabeth and Bert spotted internal waves in Hales Passage between Lummi Island and Portage Island.
Internal waves in Hales Passage
Portage Island on the left
Bellingham Bay extends behind Portage Island
Closer view of internal waves
Bert and Elizabeth have a better image of internal waves in Pacific Northwest waters http://www.raincoastgeo.org/home.html and NASA has an image from space as well:
The waves are the result of waves between different density layers in the water at depth that express themselves on the surface as very slow moving waves. A good reminder that water needs to be thought of three dimensionally.