I've spent most of my life in the ocean as a scuba diver/surfer and have encountered dolphins many times. They're just like humans in terms of personality. Some are cool, some are jerks. For example, I was surfing alone on the north side of a jetty and there was a pod that was swimming close by. One of them started slapping it's tail at the surface. This is a sign of aggression so I got out of the water and moved to another spot. Another time I was surfing about 200 yards north of a pier with one other person. We were circled by a dolphin that seemed quite playful that suddenly bumped the back of my board and then jumped out of the water over me. I've had another jump over me when I was paddling toward the wave and it was riding through it as they have been observed doing many times. If there is a juvenile with a pod I definitely keep my distance. Mama dolphin does not want to be friends with any human that comes near her baby. Quite the contrary, they will get very aggressive to protect their young. Additionally, I have seen my share of sharks and pinnipeds. Just last week a pinniped surfaced next to me and then came at me and grabbed my surfboard leash. Of course, I let out a little shriek since I wasn't expecting it but it quickly let go. I've had them follow me more than once. They've swam alongside me as I was paddling out and have surfaced right in front of me. I've had juvenile white sharks (4-5 feet) swim by curiously as well. Many of these encounters can be taken as the animal wanting "to be my friend". By the way, orcas are actually more a dolphin than a whale as they are in the Delphinidae family.