Bill,

Bald Eagles most of the time swooping low over the water and pick prey up off the surface without too getting wet.
However, they have many more methods in their repertoire and will dive, or walk, into water to retrieve food. They may land on top of a prey item (coot for instance), and float on the surface while squeezing and drowning the coot.
I've heard reports of eagles swimming to shore, dragging large prey items onto shore with them.
They may pursue other birds in order to make them relinquish the food they are carrying (gulls, Osprey, cormorants). The eagle may pick the dropped item up out of the water, or simply do a barrel roll and catch the item in mid-air, depending on the situation.
Young eagles (as young of most species) will do unusual things, including pretending to be an Osprey. After all that niche is empty in this area around this time of year :)

The above is based on literature as well as many hundreds of hours of observing eagles in the Seattle area and other parts of western WA. I'm sure there are many different observations of other more unusual hunting techniques by Bald Eagles. I would start by checking the Birds of North America account on the Bald Eagle, specifically the Food and Feeding section.

Martin Muller, Seattle
martinmuller at msn.com