Can you do dolphins on your own?

On the Dolphin Discovery website they are wayyyyyyyyyyyyyy cheaper than the Carnival excursion. Yet when I tried to buy tickets, it said they could not on that particular day. I am assuming the cruiseships have it locked down when they are in port...anyway around that?

No way around it. The cruise lines own the port and when ships are in, you have to book through the ship excursions. I guess when they own it, you have to play and pay by their rules.