http://maps.nrel.gov/mhk_atlas
This is a National Renewable Energy Laboratory link mainly about the water, such as the wave, ocean current, and tidal stream. What I found interesting is that it includes many mapping and assessment of the United States specifically. Just by clicking on the index in the right side of the page, you can easily find out the changes in the maps, presenting the changes in when and where the water changes . It also might be a helpful reference when people plan to travel.