I'd call the marina for 2008 rates and information. If you do that, post your findings as I'm sure others would like to know too.
Last year it was $50 per person, round trip. Don't know about one way. They used to take you over whenever you showed up at the marina. Pick-up times were something like 10, 2 and 4. They liked for you to make a reservation for pick-up time so they would know how many they were picking up and which boat to take over.