Captains log date - some time a while back - we went to a place in Crystal River, Florida called Three Sisters. There is a place I like to fish in the winter, that we also referred to as Three Sisters, on the other coast. This however is on the Gulf coast of Florida and easily accessed from 1420 SE HWY 19 at AAA Out board Motors (aka Crystal River Kayak Co.). You can launch your own Kayak here for a small parking fee or rent one along with all the necessary PFD's required by the people who govern our waters and play time. They are very serious about it too so make sure you have a floatation device for all in your party.
The trip from there is not too long through some very idyllic canals, under a neat bridge and on to the mouth of the springs. This is a great winter hang out for manatees, which happen to be some of the most forgiving of creatures, and they will approach you even though they are all scarred from past experiences with our kind. We actually went during the Spring, on my daughter's birthday. She wanted to play with a manatee and they were too expensive to rent so we loaded up the kayaks in the hopes of seeing some, but with the back up plan of swimming in the springs.
I have to say, we were pretty fortunate in that there was a manatee there with a rope and a float attached to his tail. He was part of a captive recovery and release program and approached us on a number of occasions while we were swimming. My youngest viewed his approaches as predatory in nature and my pushing her forward as trying to feed him. One of the "guardians of the river" approached us to tell Lily that touching the manatees would be considered naughty behavior. That's seemed a bit ridiculous and over the top so my wife chatted up the woman while my daughter got her birthday wish. Disclaimer: If we were breaking any laws in doing so then that last part was purely fictional and for the entertainment of the reader. I do not condone nor participate in such fulfilling and wonderfully enchanting experiences.