I joined a Redwood Region Ornithological Society pelagic trip to Bodega Canyon and Cordell Bank today (7 September 2014). One of the highlights was an encounter with a few Orcas (Orcinus orca). [In the photo above, there are two Black-footed Albatross in the foreground.]
The Orcas were slowly rolling at the surface. Their enormous dorsal fins would emerge one after the other and then disappear below the surface.
Below are examples of at least two different individuals. Note the size and shape of the dorsal fin and the gray blaze or saddle just behind it.
One more shot, with Pink-footed Shearwaters. The shearwaters are ~19 inches long and have a wingspan of ~43 inches. Using the shearwater length for scale, we estimated the height of this Orca's dorsal fin to be ~71 inches (nearly 6 feet)!