We took their Savanah cruise a few days earlier and really enjoyed the experience, so we signed up for the evening dolphin cruise. We arrived in plenty of time to board and get comfortable, but there were zero seats left to sit and enjoy the cruise. A couple of times the captain assured us people would move around. Yes they did, but they left purses and bags at their seats. Or one family member would remain in the seated section while other members go up to view the sights. So it's not like we could steal someone's spot. We paid a lot of money to not have to stand the entire trip.
I really didn't care if we saw any dolphins, we wanted to experience a nice evening cruise, but we ended up having to lean on the rail the whole trip as people squeezed by to get to the head, or our other option was to stand in front of people who were already sitting, another uncomfortable spot. We just ended up being salty, like the water. We did get to see a few dolphins, but we saw more on our way to Savanah a few days earlier. They weren't very active on our evening cruise.