Something strange happens in Florida this time of year. It gets cold. Sometimes the thermometer even dips below 40 degrees Fahrenheit (egads!), which is beyond cold for those of us who live here. When this happens, mist forms over the constant 72-degree water of Florida's many freshwater springs and manatees move in from their Gulf of Mexico stomping grounds to warm up in what, to them, must feel like a cozy hot tub. During the coldest months, January and February, Central Florida's springs become a -- pardon the pun -- hot spot for manatee encounters. The most famous places to encounter these "sea cows" are Crystal River National Wildlife Refuge, Homosassa Springs State Park and Blue Springs. There are also a couple of little-heralded sites that may surprise you, though -- such as off the water-cooled power plants of Palm Beach, where manatees luxuriate in the warm outflow.

However, the springs are generally a slam-dunk, and we usually sign up with PADI 5-star American Pro Diving (www.americanprodiving.com) in Crystal River, which specializes in intimate, up-close encounters with these docile mammals. I take the family up at least once a year, and our fridge is covered with manatee magnets as a result (we have that manatee license plate, too). My kids (6 and 3 years old) can't get enough of swimming with these curious creatures; when we get a cold snap in Florida, they inform me that it's time to see the manatees. So, we pack up the minivan, wetsuits and coats and go.

Encounters with the manatees start early -- usually 6 a.m. (when it's still chilly -- it's the best time to encounter manatees). The last time I was there, we met American Pro Diving's pontoon boats at Homosassa Springs just before first light. Their boats are heated and they always have plenty of hot chocolate for the kids (after the manatees, this is their secondary reason for coming). It's not long before we're in the water (it's much warmer than the air, after all). When the manatees are around, it's impossible to miss them. West Indian manatees can grow to 3,000 pounds and reach up to 13 feet in length. We'll usually see several females and their young calves in a spring-fed river, where the viz is spectacular. The manatees even come right up to the boat, often chewing on the anchor rope. They love to have their bellies scratched, and once you find a good and itchy spot, you'll be friends for life. Pretty soon, you've even forgotten about the cold. At the end of the day, you'll realize why this is one of diving's must-dos.