It lies broad and still at the side of the track, polished peaks rolling along its olive-coloured length.
I'd love to run my fingers over that back. "Only idiots get bitten by alligators," says my guide Rick, turning around in his seat and eyeing me from beneath a hefty brow. "If you get bitten, push in towards the back of the 'gator's throat to make it gag and release."
He drives on, putting a little distance between the 'gator and the idiot in his charge, before pulling up alongside a break in the spiky tangle of vegetation at the water's edge. As I clamber clumsily from the back of the van, Julie, his co-guide, hands me a thick hiking stick. "Rick'll take the lead and I'll follow behind. Just walk where he walks," she gives a reassuring smile. I return a thinner one and we step down into the swamp.
It is difficult to believe that this primeval patch in Florida's Everglades region lives and breathes so close to crops of tidy civilisation. The town of Naples – with its peach-hued homes and a beach spread thick like lorry loads of spilt sugar – is just 20 minutes west of here along the Tamiami Trail. Fakahatchee Strand, by contrast, seems sodden and brooding. Measuring 15 miles long and five miles wide, this is the world's largest cypress forest. Alligators wait gape-mouthed in its gullies; fish-catching spiders watch from their webs; bald cypress trees choke in the snaking embrace of strangler figs. I'm walking into a place where the violent wrestle for life seems unrelenting. Its wetness creeps steadily up my trouser legs.
We wade between trunks that taper high into the canopy. A blue dagger dragonfly is on the hunt for mosquitoes, skimming low over dabs of leaf-green light on the water's surface. Fakahatchee is a Native American word meaning "muddy creek", but there's no stinkiness or squelchiness. The swamp bed doesn't try to suck the boots from my toes as I lift my feet. I rub a plant and release the scent of sweet lemon and fresh grass. It's all cleaner, calmer, more fragrant than I'd expected.
"We want to demystify the swamp," Julie explains. "It's like therapy – you come in here and forget all your worries."
"But watch out for water-moccasin snakes!" Rick calls to us over his shoulder.
Set up last year, Rick Cruz Photography offers walking, photography and kayaking trips into the wetlands, but its guides have been part of the landscape for far longer. Julie Cardenas is a trained biologist, while Rick Cruz is a nature photographer with the energy of a seven-year-old and a beard like a bearskin.
The swamp is full of things that Rick itches to show me. He splashes ahead, zigzagging from branch to stump, stooping to peer into the water and stretching to lift a twig. He waits impatiently by a tree full of holes – "It's like a bunch of eyes starin' at ya, isn't it?" – and points to four woodpecker feathers caught in a wispy ball of Spanish moss. Orchids are his particular passion. We find a clamshell orchid, a dingy star orchid, a vanilla orchid with leaves like green beans, a delicate night-scented orchid in bloom; there are tiny orchids no bigger than a blades of grass. Rick maintains there are more native orchids here than anywhere else in the US.
Then I see the first mark of man, a weathered length of cable biting into the base of a tree. It was left by the loggers who devastated this habitat in the 1940s, Rick tells me. "Some wood was used for war coffins and boats, but some just for pickle barrels and stadium seats. It tears my heart. These trees were 100, 200, 300 years old." But that was a shameful episode of yesteryear; today the younger cypresses are maturing and the ecosystem is thriving. A red-shouldered hawk – the tittle-tattle bird – mews a lilting caution: "Humans are coming, humans are coming!" And they are, but they mean no harm.
It's late afternoon as we climb, dripping, from the swamp and drive a short distance to the Big Cypress Strand Boardwalk for a final stroll before the sun dips away. The elevated trail is decked with wood and dotted with laminated snippets about the strand's flora and fauna. But either side of this neat incursion, nature continues to call and to struggle and to judge its moment to pounce. A cypress tree has been tapped by a yellow-bellied sap sucker, its silver bark streaked with sticky red trickles. We stop to listen to the muffled bark of a barred owl – "Who cooks for you, who cooks for you?" – when Rick's eye is caught by a dark and rounded body 10 yards beyond a bank of ferns. "Boar," he says – and then corrects himself in an urgent whisper: "No. Bear!" The animal pauses to raise a sniffing brown snout in our direction before returning to its business, tugging at sinewy stalks of alligator flag. It feeds for a full five minutes before turning its backside to us and ambling slowly into the swamp. A black bear on my first visit. "Wow, you're lucky," says Julie, with quiet understatement. "That's only the second I've ever seen." She's lived here since the 1970s.
"Manatees guaranteed!" the brochure had proclaimed. The following day, I'm met at the marina by a man in a lime-green polo shirt embroidered with the words "Captain Barry" above a brace of crossed fishing rods; the middle of his face is concealed beneath a pair of mirrored sunglasses, the lower part under a trim, greying beard and he has a peaked cap pulled low on his forehead. My guarded guide was for many years a corporate banker, before he upped sticks to Florida and reinvented himself as the man who knows manatees. He's a New Yorker with six little boats and a wit as dry as Saharan sand. I like him instantly.
The manatee is one of wildlife's weirdos. Its blob of a body opens with a chubby muzzle pricked with whiskers and ends in a rounded tail like a salad spoon. Related to the elephant, nicknamed the cow of the ocean, and tipping the scales at 2,000lb, it could fairly be described as a portly beast. A daily graze on 200lb of fibrous sea-grass also makes it a shamelessly flatulent one. "Look out for bubbles – manatees give off a lotta gas." Sightings of this fat and farty mammal among the waves are said to have spawned the legend of the mermaid, which says much for the loneliness of the sailor at sea.
We putter gently away from the moorings in the Port of Islands Marina. A mullet flings itself skyward, twitching in mid air before landing with a belly-flop. We stay alert for signs of a manatee. A patch of surface boils and swirls before settling once more. "Tarpon," says Captain Barry. "Big fish eatin' little fish." He points to a bald eagle, an American icon sitting hook-beaked and barrel-chested on the roof of one of the waterside villas. "Wait for the currency shot ... Yeah, there it is," nods the captain with satisfaction, as the eagle turns its head to display the familiar profile on dollar bills. "Back to work," he concludes, and we emerge from the marina, follow the coast a short distance and then join a sliver of river cutting inland.
It's a rarity, the manatee; there are 10,000 or so worldwide, with populations in Africa and Asia, and a related species – the dugong – in Australia. Florida's waters host 20 per cent of that number, and this stretch of coastline, 15 miles south of Naples, buffered from the Gulf of Mexico by a sprinkling of tiny islands, is a hot spot. Manatees eat at sea but they must drink fresh water; every few weeks they ride the incoming tide to this seven-mile river so that they can slake their thirst for a day or two. The river's warmth is a refuge during cold snaps. Despite their blubber, manatees are very susceptible to low temperatures; 400 perished from hypothermia during a recent harsh winter.
Today is warm. The sides of the river are crowded with mangrove trees, dangling bony roots into the water like rows of skinny schoolboys cooling their feet. A stringy bird makes a ragged descent and lands heavily among the branches. "Ancient Egyptians believed the ibis carried them from this life to the next," says Captain Barry. It must have been a bumpy journey, I decide, as the white bird shakes the twigs from its feathers. A muscular, shoe-sized bull shark – one of the few of the predatory species that venture into fresh water – makes its swaggering passage beneath the boat. But still no manatees. A belted kingfisher breaks cover and flies frantically across the water, its black wings blurred with vigour.
Two hours pass without the faintest whiff of a windy herbivore. "They ain't playing ball today," says a tight-jawed captain. He spins the wheel to take us home; the brochure curls in his back pocket like the sneering lip of a hollow promise. But as we chug along the final straight of the manicured channel that leads to the marina, Captain Barry suddenly cuts the engine and mouths a relieved "Bingo!" There, in water that is as black as a crow's eye, a tan-coloured shape cruises beneath a wooden landing stage before heading out of the shadows and losing us behind a thousand shards of sunlight. We wait. After a few minutes there's an abrupt hiss from a blunt nose five yards away; the manatee hangs in the water, nostrils flaring as it sucks hungrily at the surface. It's beautifully ugly, with deep-set eyes like currants in a bun. Bubbles stream from somewhere below. And then, with a lazy paddle of its broad tail, the manatee dives once more. "I think it's dugong," I joke, and a pair of scarlet-faced vultures make circles overhead.
How to get there
Adrian Phillips travelled with American Airlines (aa.com); a return from London, Heathrow to Miami International (via Boston) costs from £468. Naples is a two-hour drive from Miami. Dollar Rent-a-Car (dollar.co.uk) has Economy Cars (Chevrolet Aveo or similar) from £110 per week. Rick Cruz Photography (rickcruzphotography .com) runs guided swamp walks (£45), photo safaris (£75) and kayak tours (£40) lasting for two to three hours.
A 90-minute eco-boat tour with See Manatees (see-manatees.com) costs £23 for adults and £17 for kids (money back if no sighting).
Where to stay
The Inn on Fifth (innonfifth.com), Naples, has doubles from £97. The beachside Hilton Marco Island Beach Resort (marcoisland.hilton.com) has doubles from £87. Glades Haven Cozy Cabins (gladeshaven.com) has characterful wooden cabins from £55; the adjacent Oyster House Restaurant serves good value local produce, including stone crab.
Go to paradisecoast.co.uk