Brown Pelicans forage in shallow bodies of water like Bolinas Lagoon by skimming low over the water surface as this one is doing; they then capture fish by diving in a low trajectory. By contrast, over deeper water, they fly higher up and when they sight fish they capture them with a spectacular vertical dive, as shown here a short distance from the lagoon on the ocean side of the Stinson Beach peninsula: http://www.pbase.com/image/167752747 .