I went last Feb. it was SOOO FUN!!!!! we went on the afternoon tour, the only down side was by the time we were done it was getting a bit chilly. There's not much sun due to the dense jungle. We went via NCL even though we usually book our excursions independently because the driving is a bit scary in Jamaica. The road to get there is VERY narrow, winding and high!
Bring your water shoes, the river area is a bit muddy and yucky to step on. You can buy them from the locals but I'd just wear/ bring them.
Along the way there are photographers which are for sale at the end of the river. Also a place for a few beers/ snacks. Very fun for all ages!!