Ocean Sightseeing Reality
The reality is that cruise ships are trying to accommodate a lot of people. They don’t always have the money or connections to set up tours of the biggest tourist attractions. Sometimes you are stuck with boring scenery and uninteresting tourist attractions. I wouldn’t hold my breath waiting to see a dolphin either.
Depending on where your ship is , the weather, the time, and the stubbornness of the nearby dolphins, you may never see a single one. There are other animals put there in the ocean so odds are you are bound to at least see one. Whether or not it is picture worthy is all up to you. I say take pictures of everything.