Do you know if you can get in the water with them or not?
No, you cannot get in the water with them.
The Florida Manatee Sanctuary Act states, “It is unlawful for any person at any time, by any means, or in any manner intentionally or negligently to annoy, molest, harass, or disturb or attempt to molest, harass, or disturb any Manatee.”
Courts have consistently held that this means, if they swim up to you it is okay to look at them. Reach out to touch them, though, and you face arrest. Swim towards them... Same thing, big-time fines and/or jail time.
Yes, every year a lot of people get away with harassing manatees, and don't get caught. It warms my heart, though, every time I read about someone doing jail time, or facing bankruptcy-level fines, for thinking that they could swim after a manatee, pet it, play with it, whatever. They are not pets. They are a seriously endangered species. Please look, but otherwise leave them alone!