Dolphin Discovery in Cozumel

Hi,

We will be traveling next month and one of the cruise excursions is Dolphin
Discovery. If we book through the company directly we can save about $60.
If anyone knows of this operation I have a few questions:

1. How much is the taxi from the cruise terminal to the park, round trip?
2. How far from the platform is the observation area, as my wife is not
sure if she will participate or just watch? From the observation area will
the observer be able to take good pictures/video?
3. Other than including transportation is there any reason to book through
the cruise line?

Thanks!

Eddie G