A few to pick from. I got quotes from many of these for CA to RT and back. Depending on which you pick and how many in group, be prepared to pay around $350 per person round trip, including land taxis, fees, and taxes. We were quoting a group of 10+, and best I could find was $320pp. Those fees and taxes comprise half of the quotes by the way.

On the other hand, if any of the ferries schedules work, they will be 50% less, including all taxis, fees and taxes. A lot of painkillers to be had with the difference....

Island Time Water Taxi
Chillout Charters
Sensation Ferries
Ocean Dreams
Seahorse Water Taxi
Dolphin Water Taxi

As to Dolphin, they responded to quote request through their website, as did all of them, but I could never get Dolphin to return my phone call either. Quotes usually returned within one-two business days.