Excuse me for saying this, but swimming with a pack of Orcas is just stupid. Those things are intelligent predators that know how to work as a team, and you are not safe even when on a boat, if you are constantly leaning overboard on it. Via Buzzfeed.com.
Below is a small example of how they can make out a plan, communicate it amongst each other and do some serious teamwork. I guess they would hesitate attacking humans … but if not, you would be toast compared to the seal.