We booked the early morning (630AM) tour with our hotel and drove to the pickup spot. The guys on board were very helpful and there were lots of refreshments. The trip was good, and we saw lots of fish and turtles. Returning around 9AM this was just the right amount of time for the tour, and we could enjoy the rest of our day. There were approx. 20 people on our trip!
Note: The hotel where you park is valet only, so be sure to bring some cash for a tip (we didn't).