‘Good morning”. It’s the fifth greeting I’ve had in the same number of minutes and for a Londoner it feels a little unnerving.

“Good morning”. There’s another one. Another bronzed, serene looking senior passes me and smiles. It’s 8am and I’m one of many joggers taking advantage of the cooler morning at the beachside running track. To one side, there’s the kind of white sand that’s good to run through your toes. To the other, hotels, diners, Tiki bars and an enormous pirate-themed mini golf course. Cyclists, power walkers, even rollerbladers with their dogs; every single person looks me in the eye and offers a greeting. It’s surprisingly uplifting.

I’m in Clearwater, Florida, one of the most popular beach towns on the state’s Gulf of Mexico coastline, where the sea is indeed clear and a post-run swim is invigorating and refreshing.

And for 45 years, it’s been home to dolphin and turtle conservation at Clearwater Marine Aquarium across the causeway where Bill Potts greets me and shows me the ropes. While the beach is filled with sunseekers, dedicated teams of vets are undertaking their weekly rounds of the aquarium’s resident turtles — some end up tagged and released, but others, unable to fend off predators, will remain.

“It’s like a five star hotel,” explains Bill. “Each dolphin, turtle or otter has a personalised diet down to the last gram, we’ve worked out exactly what they need in terms of rehab and food.”

The organisation even has a dolphin ambulance to help mammals which become beached or injured along the coast, while the true story of one inhabitant Winter, who needed a prosthetic tail fitted, formed the basis of Hollywood movie Dolphin Tale in 2011.

Its marina still welcomes actors such as John Travolta and Tom Cruise but the wildlife at Clearwater Beach rivals any celebrity spotting.

I head out on a dolphin cruise with The Tropics Boat Tours, swinging past Bird Island, a man-made sanctuary for the area’s birdlife. No-one is allowed to set foot on the island, but from the boat I spot spoonbills, ibis and herons, as still as sentries.

Heading out through the break in the land that separates Clearwater Bay from the sea, sailing past Sand Key — one of the most beautiful beaches in the state — we spot a pod of bottle-nosed dolphins who trail us for a while.

The next day, I head east to Weedon Island Preserve to meet Russell from Sweetwater Kayaks. His is the only company allowed out on the preserve and his gruff hippy exterior hides a total passion for the Floridian mangroves.

Part of Tampa Bay, which separates this outer peninsula and its sandy outer shell from mainland Florida, the preserve’s calm tidal waters are home to black and red mangroves, stingrays, dolphins, sharks and manatees.

Native Americans lived amongst the swampy inlets in this rich ecosystem for thousands of years but the route I paddle was made possible by a 1950’s initiative to dig huge ditches through the area to combat the mosquito problem. It didn’t work but it does mean kayaks can explore this tranquil spot.

Russell and I glide through the shallow water, his paddles dipping and pulling seamlessly through the water without a sound. Mine are splashier as I try and remember any form of technique. I spy stingrays underneath us and keep an eye out for sharks as we head for one of the mangrove tunnels.

It’s only wide enough for one kayak and the gnarled ancient spidery roots of the mangroves have formed a perfect arch over the water. There’s a complete absence of sound as I pass by the black knots of tree; everything is so still that where the water meets the horizon I can’t tell what’s below and what’s above me. It feels like Alice in Wonderland and her rabbit hole.

A network of boardwalks and trails snake across the various islands and lowlands too, but it’s time to head to drier land over in St Petersburg.

Once known as ‘God’s waiting room’, it’s now one of Florida’s hippest cities with a progressive mayor who’s overseeing attempts to become the state’s most sustainable place to live.

The downtown city’s wide low slung, red brick avenues are full of indie coffee stores and immaculate street art while the white sands of St Pete’s Beach were once a favourite of the east coast elite. The coral pink Don Cesar hotel was a haven for movie stars and the New York Yankees (who even bailed the hotel out when it ran into trouble post-Depression).

But there’s so much more to do than sunbathe. A flat landscape and over 330 days of sunshine a year make the area a dream to cycle, with a bike rental scheme being trialled in the town. I have the Fred Marquis Pinellas Trail in my sights. It runs for 47 miles from St Pete north to Tarpon Springs, following an abandoned railway route.

With nine art sculptures over the course of the trail, you can veer off on other cycle routes which run parallel to the beach or criss-cross the pretty little peninsula too.

After a morning exploring, I follow a local tip-off to discover Locale, a market-cum-upmarket-takeaway-cum-food-hall offering vegan salads and pizza made in front of you, a fishmonger, wine merchants and plenty of local artisan producers, plus a sit-down restaurant. I demolish a cheeseboard and a cocktail in the name of research and people watch.

It’s like wandering into a sunnier, happier version of Seattle or Portland, thanks partly to the craft brewing industry around Central Avenue with its informal self-guided brewery tour, many doubling as neighbourhood bars. As I stroll past bikes and skateboards lining the pavement, I find it’s only taken a few days in Florida and now I’m the one smiling and greeting strangers that pass by.