I don't have much time tonight, but here are a few more photos from the offshore boat trip on 9 October 2016.
Can you see the pale triangular dorsal fin hidden within the splash in the photo above?
The dramatic splash itself is also a helpful hint used to identify this small cetacean.
Dall's Porpoises (Phocoenoides dalli) are known for their black-and-white patterning, their fast swimming speed, and their high, "rooster-tail" splashes.
In the image below, look for the white patch along the left side, the white at the trailing edge of the tail, and the white on the dorsal fin. (There is also a textured white area in front of the dorsal fin — that's a concentration of bubbles.)
And here's another example of that dramatic splash. The splash makes it easier to identify Dall's Porpoises even when seen in the distance.
While Harbor Porpoises can be seen from shore, in this area Dall's Porpoises are most often encountered further out to sea. If you're on a boat offshore of Bodega Head, keep an eye out for these handsome porpoises.