IN FLORIDAS CRYSTAL RIVER SPRINGS, a mammal exists somewhere on the margin between reality and imagination. It grows to 3m long and can weigh more than half a ton. It has a streamlined body, its skin is thick and wrinkled and it has two front flippers, each with three or four nails, and no hind limbs.
     It might be some weird seal or walrus if it wasnt for its strange, paddle-shaped tail, but its closest relative is, in fact, the elephant.
     Its difficult to explain what a manatee is to somebody who has never seen one. How sailors of old ever managed to mistake these obese, whiskered animals for mermaids is hard to imagine, but the word manatee derives from the Native American manattoui, which means womans breast.
     Floridas manatees, Trichechus manatus latirostris, would surely have become extinct had they not been protected. Now they are a real tourist attraction, represented everywhere, from T-shirts to postcards, from numberplates to newspapers. And in Crystal River National Park in the north-west of the state, you can dive with them.
     Manatees live in shallow waters - slow-moving rivers, estuaries, saltwater bays, canals and coastal areas, especially where seagrass beds flourish.
     Their normal lifespan is 50-60 years, and manatees have few natural enemies. In fresh water, alligators or crocodiles can plunder the calves, and in the sea big sharks may pose a threat.
     They appear unafraid of humans, but humans have been the manatees real problem. Because they can provide tasty meat, high-quality oil and hardy leather, manatees were once hunted ruthlessly. In 1950 alone, more than 38,000 Amazonian manatees were killed.
     Nowadays they face other dangers. In the past decade, 150 died each year because of damage to their habitats, or encounters with the propellers of boats or the locks in Floridas channels.
     Fewer than 2000 remain in the world today. The majority live in the zone between the Gulf of Mexico and the Caribbean, including Crystal River. There are some 1200 West Indian manatees in the USA.
     Manatees are half a ton of love and tenderness. In six years of observation, the only halfway-aggressive action noted by researchers was one blow of a tail from a mother on a calf.
     For these animals, sex is a joy and violence doesnt exist. They are sociable and playful, and like to chase, play follow-my-leader and bodysurf. Caressing each other is an important part of their lives.
     They are inquisitive, and can transform objects fallen to the bottom into playthings. And they have a real group
     consciousness, to the extent of helping out any companions who are injured or get into difficulty.
     Manatees are also very lazy and, between meals and games, enjoy short naps. They either stay motionless on the surface or drive their faces into the bottom, in a condition of apparent trance.
     Their enchanted singing is a myth. Manatees emit continuous sounds within human auditory range, but these are muffled grumbles, or squeaks and squeals when they are frightened, playing, or communicating, as between calf and cow. Perhaps our ancestors got confused with the songs of humpback whales amplified by the keels of their vessels.
     Manatees browse on algae and aquatic vegetation seven or eight hours a day, and by night may go ashore to eat plants growing out of the water. This is the habit which earned them their other name of sea-cow.
     They can eat up to 90kg of grass daily. This is why, in Florida, manatees have been put into canals and rivers to help rid them of infesting plants such as water hyacinths, which can hamper navigation.
     They use their flippers to help them pass food into their mouths, where they grasp it with flexible, split upper lips which resemble pin-cushions. They shake algae carefully to remove sand and small animals before putting it into their mouths, or else, after pulling it up from the bottom, leave it to decant.
     Each half of a manatees jaw has five to eight molars which, unusually, are continuously replaced throughout its life. Horny-ridged pads protect jaw, palate and tongue.
     Manatees have a very slow reproductive rate. Females mature at between five and nine years old and may mate with several males. Gestation takes around 13 months and they can give birth every 2-5 years, usually in spring
     or summer. The mothers carry their calves around tenderly for the first year, after which they become independent but still live within a family group that includes the fathers.
     Like all mammals, manatees breathe using lungs, so must come to the surface every three or four minutes. One breath through the two nostrils on top of their muzzles provides a 90% air exchange, compared with humans paltry 10%.
     But they dont dive deep - their free-diving world record is only10m! They live in the 2-6m range, and dont like water cooler than 22C. If the temperature falls, they leave the coast and swim upriver.
     And in summer, they can range along the coast to Louisiana in the west and Virginia and the Carolinas to the north. Researchers have noted a manatee covering 155 miles in under four days - surprisingly fast for an animal that normally cruises at 5mph, but if they want to, they can accelerate to 18mph.
     Youll find manatees in the Crystal River, and particularly Kings Bay, from November to March.
     Fly to Tampa or Orlando and hire a car - Kings Bay is about 90 minutes from Tampa and accommodation there ranges from lodges to hotels.
     Manatees normally avoid scuba-divers and their bubbles but are merely curious about snorkellers, so the tube is the best way to travel.
     Dives can be made from small, low-powered boats you can drive yourself, though several resorts organise guided excursions. You will be given maps and told the best areas to see the manatees.
     The important thing is to play by the rules and treat these mammals with sensitivity. Boats should be driven slowly to avoid harming them as they surface, and should never be taken into the buoyed sanctuary areas, which are supervised by rangers.
     In the water, never chase or approach a manatee; let it make the running. And dont ever try to isolate an individual, or separate a calf from the mother. Her instinct is to interpose her body between her calf and any intruder, or take flight with the calf if she senses real danger.
     Manatees should not be fed, either. If they become accustomed to being around people, it may alter their behaviour.
     One thing is sure, you will never forget your first encounter with the manatees, and the amazed expressions they wear will always make you smile!

One of the 1200 West Indian manatees that live in the USA
a mother with her calf
hanging out in the shallows
an inquisitive baby plays with a snorkellers fin

Plantation Inn, www.plantationinn.com,
001 352 7955797
Crystal Lodge Dive Centre, www.manatee-central.com,
001 352 7953171
Port Hotel and Marina,
001 352 7953111
Kings Bay Lodge, kingsbaylodgefla.com,
001 352 7952850
American Pro Diving Centre,
001 352 5630041