We went on a tour (2 persons) in the beginning of February with Captain Ron and diver Lauren (if I'm correct) and we were in a group with three other women. We went on an early tour, 6.30am, which I definitely recommend. With this tour you are one of the first people in the water and not overwhelmed by other groups and tourists. On our way to the three sisters springs we came accross some bottled nose dolphins: AMAZING! Ron and Lauren were very helpfull and kind and gave us a lot of information about the manatees and the environment.
Overall, the tour was succesfull; we saw a lot of manatees and one came really close! For me, it would have been better if we sailed to other places other then the three sister springs, just to see some more instead of floating in one area for +/- two hours.
However, I do definitely recommend booking a tour at this company, because they know what they're doing, they are helpfull and give you a lot of information.