A few months after returning from our safari outing while on our world cruise, I was a little unnerved by the report of a woman who died after being mauled by a lion in an African park. She was in a car. We were in an open sided land rover. The difference was the type of park and that we had guides and we followed the rules they set.
There have been other encounters with wildlife on our travels. In Australia, we fed kangaroos and emus. While they seem safe and are very used to people, they still are wild animals and can be unpredictable. There are safety guidelines probably the most important being if the animal wants to move away, let it. And it goes without saying that any animal that feels cornered will defend itself. Kangaroos have powerful legs that can do a lot of damage.
While I've never been in the water with a manatee, we have been on the water in a kayak and had some close encounters. We had one youngster that pushed our kayak a bit like we were a water toy. We suspect that some kayakers, against Florida wild life regulations are encouraging the encounters by giving them fresh water from bottles. There are manatee encounters through some tour operators in Florida. If you opt for that, be sure to pick a reputable one.
Probably one of the most exciting encounters we had was diving with dolphins. Two trained dolphins followed our boat out to water about 40 feet deep and, after a little training for us, performed several behaviors with us including a kiss on the cheek. The amazing thing was one moment the dolphin had its nose against my hand demonstrating its strength by propelling me in a circle and the next it was gently brushing against my cheek.
But each encounter held a risk. A wild animal is a wild animal and unless you follow the directions of reputable people who have worked with the animals, you leave yourself open to a very bad situation. Enjoy the encounters but do your research, find a good tour operator and then follow their direction. The results will be well worth it.