The trip is free. We went on a Sunday when there were no cruise ships coming in. We were some of the only people there. I spoke to a friend who was on a cruise ship and they said it was mobbed the day they went.
Bring water shoes, you don't want to rent them. Enjoy.
I agree with Samantha. The bus leaves from at least CTI almost every morning at 9? We also went on Sunday and were the first group there. We were back at the resort by 11:30 or so. Good excursion as long as it isn't packed.
Tip: When you are done, you will have an option to go left or right to get back to the bus area; go left and avoid the village, unless of course you want to buy something. They have a tendency to divide and conquer tourists.
ask at the events desk for the best time to go, they usually know when the ships will be in and they'll tell you the best time to go. the trip is free but you will want to have money to tip the driver and the guides. when you're done and walk through the craft village just say no thank you and keep moving. they're not as bad as everyone makes out, the people who work at the kiosks in US malls are far worse then the people in the craft village at dunns river.
take water shoes and a water proof camera. have fun