Getting from Dolphin to Universal with 9 people

[ms.yt]

I'm going to be staying at the Dolphin for a convention. I will be the chaperone for 8 high school kids, and we won't have our own transportation. The kids would like to spend a day at Universal, but I'm not sure about our transportation options. I think we have too many for an Uber or a cab. Is our only option booking a Mears shuttle or something similar?