It's funny that, while suspended 335ft above the beautiful Florida skyline, I can neither see nor hear a single shrieking child.

But as I sit on the edge of the world's first vertical drop tower - complete with 90-degree tilt function - I don't really notice anything that's going on around me.

Up until now, I'd convinced myself that Falcon's Fury - internationally renowned theme park Busch Gardens' towering centrepiece - would be a breeze. I'd already bottled it three times, but now, looking down at the ant-like crowds below me, there's no turning back.

Summoning an imaginary shield of courage, I grip tightly onto the buckle around my waist. I can still taste the waffles I had for breakfast, and I fear I may be reunited with them very soon.

An invitation to spend the half-term holiday at a theme park popular with children would normally be met with a series of excuses from me: Sorry, I'm cleaning out the loft; Sorry, grandma is coming to stay; Sorry, there's a Peak Practice omnibus running on UK Gold.

But I'm surprised to discover that Florida's popular theme parks are not heaving with small, screaming children. In fact, most of the "screaming" appears to be coming from adults - including myself.

I'm visiting Discovery Cove, SeaWorld and Aquatica to find out why scary rides and animal attractions are still just as much fun for adults.

It's not that these venues are child-free zones at all. In fact, during my stay, I bump into several school trips, as well as families crossing the Atlantic to enjoy a welcome bit of much-needed Vitamin D. But the parks are so vast and well laid out that there's enough space for everyone.

Like the best children's films, laced with references that will have mums and dads nodding wryly in recognition, the USA's top tourist attractions seem to cater for all tastes.

I'm just amazed so many kids are brave enough to tackle these rides. I'm certainly pushed to my limit at Aquatica's daunting Ihu's Breakaway Falls. The set-up is simple - a cylindrical, vertical-drop flume with twists, turns and a countdown clock.

The trudge up to the summit of the ride - which, for those wanting a distraction, allows the chance for magnificent views of the Orlando landscape - is conducted in silence.

Three participants at a time are then placed into solo tubes, upright and facing each other. As the countdown clock ticks away in inverse proportion to the ascending heart rates, so too the tension builds. Then, one by one, trapdoors open under each flume and the twitching riders disappear from sight.

Fortunately, the pace is altogether more tranquil across the road at Discovery Cove, where the Lazy Rapids represents the most terrifying thing in the whole park. Floating effortlessly like an autumn leaf on a stream, it's almost possible to drift into a slumber as the 15-minute course loops around the park again and again.

One of my highlights though, is a safari through Busch Gardens. I'm able to glimpse rare and endangered animals and learn about their plight at the hands of poachers.

As our 4x4 limbers over uncertain terrain, my guide explains that much of his daily work is dedicated to educating people about wildlife and spreading awareness.

There are also opportunities for close contact with animals. At Discovery Cove, I'm able to swim with dolphins, while at SeaWorld, I'm invited to help feed the stingrays. It's my first encounter with the pancake-flat fish, and I find the whole experience quite daunting.

But in a week where my courage has been tested to new heights, I'm more than ready to embrace new adventures. The stingrays seem to enjoy it too.

TRAVEL FACTS

:: Ryan Hooper was a guest of SeaWorld Parks & Entertainment (www.seaworldparks.co.uk). The Discovery Cove Ultimate Package includes one day reservation at Discovery Cove - with 30-minute dolphin swim experience, all meals, snacks and beverages - plus 14-day unlimited entry to SeaWorld, Busch Gardens and Aquatica. Prices start from £175 per person.

:: British Airways (www.ba.com; 0844 493 0787) flies from Gatwick to Orlando fourteen times a week and Gatwick to Tampa seven times a week. Prices from £553.06pp.