A few years back while Blackfishing in early November, we were visited by a bottlenose Dolphin. He showed up 3 times over the course of 3 hours whenever I started the motor. The distinctive sound of the Honda 4 stroke must have reminded him of someone else. None of the other 4 boats near by were paid a visit. He followed me in for about 2 miles and played in the boat wake when I headed in.
The picture below is the tail of a Giant sunfish (Mola Mola) They are the size of a large coffee table or desk. I have seen them a half dozen times usually in August or early September. They lay flat to the sun with their tail coming straight up and back down flat to the water.
I have also seen seals and even a Deer swimming by on two separate occaisions. These sightings are pretty rare, but add to the adventure of every trip, as they are not all the same.