A long line of key after key with a lot of diving on offer - thats the southern spit of Florida.

I CAN SEE THE SHAPE OF THE DIVER who has just jumped in immediately below the boat, and hes finning. But hes going nowhere.
OK, there may be some current, drawls the skipper, squinting over the side. Dont look down now! he warns me, as if the sight of the sea is about to scare me off - and I roll backwards.
I hit the water and Im in a state of shock; its 30°C. Im diving in a bath! No wonder they laughed when I pulled a drysuit out of my bag...
I grab the granny line and haul myself forward to the bow, and the point where the boat is tied into a permanent buoy. This is wreck-diving Florida style; the boat anchors in and you fly like a flag in a breeze all the way down - and back up - the fixed line.
Theres no such thing as slack here: if the buoy has been pulled under water, its regarded as a fair indication that the current is too strong to dive.
I have barely arrived in the Florida Keys and Im still in a state of serious cultural disorientation as I handle my way down the line, avoiding the mussels and embedded fish-hooks.
Were diving the Adolphus Busch, an upright 210ft freighter deliberately sunk in 1998. At 30m (or 100ft in American) its still light and bright down here.
The wreck is famous for its resident large groupers (or jewfish in American), and for the opportunities offered by the many holes in its hull to divers who enjoy a bit of wreck penetration.
On a normal day with the usual 15m viz, its a superb wreck. Today, its snowing under water in a way thats vaguely reminiscent of conditions more usually found on the Countess of Erne in Weymouth harbour. With the heating turned up.

If you love a good wreck dive, the Florida Keys are littered with opportunities. Most are artificial reefs, but many have interesting enough stories for a Shipwreck Heritage Trail to have been established by the Florida Keys National Marine Sanctuary.
History aside, bigger is definitely considered better here in Florida. Hence the sinking of stonking great wrecks like the Spiegel Grove (510ft) and Oriskany (888ft). The decommissioned USAF missile-tracking ship General Hoyt S Vandenberg (523ft) is set for sinking off Key West before next summer.
This is fantastic for divers, but sport-fishing is a far more significant market here. This may help to make sense of some of the local sensibilities, including broad toleration of divers with spearguns, and lobster-hunting.
If your motivation to dive wrecks is to rip off lumps of brass, this probably isnt the place for you, but if you believe that too much of a good thing can be wonderful, youve struck gold.

Approaching the Keys by driving south from Miami, you get an impending sense of impermanence. The sky seems to squeeze the string of islands, and the thin grey highway - US Route 1 which binds the Keys together - against the sea.
There are no tall buildings, and aside from the low-lying city of Key West, theres nothing you could call a town.
All life clings to the matted mangrove roots that form the foundations of this place. One large wave, one extra big tide, one big fat hurricane, and you feel as if it would all disappear back into the sea. Which is exactly what the place tries to do; every so often.
Seventeen hundred islands make up the Keys, but everything revolves around the Highway with its many bridges. All the Keys are different, except for Key West, which is so different.
The people are as big as cars, the cars the size of houses. The idea of switching things off to save the planet has yet to reach Florida. In any case, it would probably be regarded as an attack on the constitutional freedom to consume to excess and, therefore, a Communist plot.
Over here, minimalism is something you would seek surgery for.
The breakfasts resemble a Homer Simpson cliché and the coffee is vile. Dont panic when you see dolphin on the menu, it isnt dolphin - just relax, breathe and stop expecting the words and the meaning to go together.
If you find youre feeling strangely nostalgic, itll be your car radio. Florida stations fell into a loop in the space-time continuum somewhere in the late 70s and music made after the Eagles split is unknown here.
Dont mention the war, obesity or any kind of politics. In Florida its still legal to execute anyone with political views that are vaguely left of neo-Nazi. Unless they promise to confine themselves exclusively to Key West.

Theres no wind-chill factor as the boat speeds across the shallow turquoise water towards the next site. Its like standing in a hair-dryer. You could live and dive in a bikini here - if you have a large vat of sunblock for the day and another of insect repellant for the evening.
With the less-than-perfect viz, the skipper is acting fairly nonchalant about whether we get off the boat for our second dive at the shallow marine reserve of Looe reef, and I get the impression that this is a sub-prime dive site. I am hideously wrong.
The reefs here are shaped like fingers, and it should be reasonably easy to navigate your way around and back to the boat, but inevitably you bump into a ray or a shark or a turtle and end up in a spin, so do take a compass!
If you love the kind of pretty coral you get in the Red Sea, you may initially be disappointed at the slightly scruffy appearance of the corals here. Dont be put off. The real wow factor is the size and abundance of the marine life.
I spent the dive squeaking and squealing into my reg with delight at the reef sharks, nurse sharks, morays and the dancing, spotted eagle rays.
I saw more marine life on one dive here than Ive seen in a whole week at other destinations.
I climb back on the boat with a huge smile on my face. Suddenly, everybody is talking to me. Im still English and decidedly weird, but my enthusiasm has broken the ice. Note to self: drop your inappropriate English reserve, youre not in Stoney Cove now.

Ive noticed that people here dont actually understand what Im saying. The words are clear enough, but the meaning seems to have wandered off.
Take coffee: here, its brown water without any actual coffee in it and they add a white chemical called half-and-half rather than milk.
I find myself laughing in disbelief as the waitress pours it into my cup.
I could kill for cappuccino.
Were about to visit the fabulously bizarre Underwater Music Festival, but theres a major obstacle: me.
You dont have a PADI card The woman behind the desk in the dive centre looks at me as if Ive just farted.
It takes an hour and some special pleading by fellow-journalist Tom Morrissey to persuade them to search the PADI database and dredge up an ancient cavern-diving qualification taken in Spain in 1998. Phew! I am officially a diver. Fair play to the efficiency of PADI record-keeping.
A flotilla of small boats is strung out across the mooring buoys at Looe Reef when we arrive - this is a major happening and a top day out for locals and tourists alike.
The musicians are dressed as various rock stars, complete with weighted wigs and accessories.
They kit up over their costumes and jump in with their instruments to jam on a patch of sand.
The music is piped beneath the boat and theres a simultaneous broadcast on the local radio station. The fish appear to be lapping it up and I almost trip over a nurse shark that has come in close to investigate the tunes.
The whole idea is surreal, totally nonsensical. But here, in the context of the Keys, it just works a treat and it feels natural to bump into a mermaid and a Marilyn Monroe look-a-like posing under water on surface-supplied air.
Where else in the world could you possibly experience this

This is an ADVANCED dive, warns the man in the dive shop, giving me a severe look. Its VERY deep. Well that told me, then!
The buoy, one of eight on the wreck, looks to be surfing for its life as we moor into the Spiegel Grove - a massive, upright wreck of a US Navy landing ship.
It takes both hands to haul myself down the taut, singing line.
Schools of bright blue fish vibrate with the effort of staying stationary in the current, and I have to keep my face forward to avoid the possibility of having my mask ripped away.
Barracuda are hunting around me as I climb downwards. As the line splits, I take the direction indicated by an arrow that leads over to the wreck, arriving like some kind of trapeze artist on the forward guns.
Wahay! A bit of a nark, a bit of adrenaline, a bit of super-sized military hardware, who could ask for anything more
Spiegel Grove hit the headlines in 2002 when she went belly-up during attempts to sink her. The air-filled bow was left protruding out of the water, and the ship finally settled upside-down, with tugs and commercial divers employed to roll it onto its starboard side.
In 2005 Hurricane Dennis intervened and righted the wreck.
Dwarfed by the physical presence of the wreck, its immediately apparent that the site requires a number of dives even to begin to do it justice. I could happily dive here all week without getting bored. With a single cylinder and the limitation of no-stops, you can only expect around 25 minutes at the 30m depth to explore.
Theres barely time to snatch some photos and witness an epic bust-up between a tarpon and a barracuda on the foredeck before sneaking a peek at the accommodation. The briefing included a stern dont go inside the wreck warning. Three divers recently lost their lives after getting lost inside.
Straying beyond the lee of the wreck is a bit like turning a corner into a gale. Its a monster wreck and I should be finning like a nutter to see as much as possible, but conditions encourage you to explore the area on which youve been dropped.
I would hate to disobey the skipper and either come up the wrong buoy, or - mega-embarrassing - get swept off the wreck, and have to float about until everyone else is back on the boat.
I can understand why local operators define this as an advanced dive - the stern man is forgiven. You need stamina to deal with the current and discipline to follow the safety briefing. I like to believe that these are qualities that British divers possess in bucket-loads.

I TAKE A DEEP BREATH as I walk into the Silent World Dive Shop; Im expecting to do a lot of explaining before Ill be allowed on the boat. To my delight, theres a big BSAC banner in one corner and the owners are a young English couple, Alison and Chris.
Theres no hassle and I am given nitrox. The centre even runs a Wreckfest every September for wreck addicts.
We set off for the Duane, a shipwreck heritage wreck and another 30m dive. Its a 327ft ex-Coast Guard vessel with a proud history and a fabulously iconic radar mast.
The mast and its swirling frenzy of fish is clearly visible as I descend.
Theres not much current at the surface, but once I drop onto the wreck, its ripping along. Were right on the edge of the Gulf Stream here, which has a massive impact on the diving as well as ensuring an abundance of predatory fish such as barracuda.
Theres ample opportunity to swim through the navigation bridge and the wheelhouse, sheltered from the current. Its an impressive wreck, recognisably retaining its original features. You can easily picture it in action in WW2, hunting down the German sub U77.
Our next wreck is the Benwood, a 360ft gem lying at all of 10m, and a genuine WW2 casualty. She collided with another ship, the Tuttle, in April 1942, while both were sailing at night with no lights to avoid the attention of U-boats, and sank after damage to her bow and cracking her keel.
The wreck is fairly flattened - having been salvaged, blown up as a navigation hazard and then used as an aerial target. Despite this, the Benwood is still recognisably wreck-shaped and the bow is a prominent feature.
The wreck is home to an abundance of marine life, including a rogue pair of nurse sharks that appear immune to the interest of divers. My safety stop is spent looking down over the entire wreck site in the company of a cruising barracuda.
I would gladly revisit every one of these sites; Ive barely scratched the surface of the available wrecks, and before I can rinse the salt off my kit theyll have sunk something else!
The Munro County tourist authority website describes Key Largo as the diving capital of the world - a tad boastful and self-regarding, methinks, though this is a fair reflection of local sentiment.
I would prefer to paraphrase a Key West sentiment: so many wrecks, so little time...

If you want to take a break from diving, or youre bringing a non-diving family/partner, a wealth of amazing activities are on offer.
My favourite place was the Turtle Hospital at mile marker 48.5 on Marathon Key, which sports the slogan Rescue, Rehab, Release. The Keys are home to a number of different turtle species and youre likely to encounter at least one turtle on the reef dives.
This facility appears to be staffed exclusively by teenage girls on internship (volunteers) who so clearly adore the creatures they care for that its difficult not to be enthused by them.
With turtle nicknames such as Bender, Bubble-Butt and Randy Rudy, whats not to love about the place
Turtles are not as glamorous or attractive as dolphins are, and theres nothing commercially slick about the operation. For these girls its a labour of love, a rare commodity in a land where the accumulation of wealth is regarded as a moral imperative.
Having spent some time listening to the various woes of the turtles and meeting the eclectic characters cared for at the hospital, I felt compelled to ask Whitney, the animal-care co-ordinator, if she had any tips for divers.
At this point the entire staff went into a frenzied discussion about what to recommend and came up with a list: dont grab or harass turtles; dont litter, and remove any litter you find on a dive; help to protect habitats below and above water; and report the location of any injured or sick turtle to the appropriate authority. Please bear the list in mind wherever you dive with turtles.

Opening on the Spiegel Grove wreck.
Gun turrets on the same wreck.
Nurse sharks can be seen at many sites
Spend bottom time in the toilet cubicles on the Spiegel Grove.
Performers at the Underwater Music Festival - sound quality leaves something to be desired.
OK, I surrender - undignified pose at the Turtle Hospital but they all mean well.


GETTING THERE: Fly direct to Miami with Virgin, BA or a US airline, hire a car at the airport and drive south. There is also a shuttle bus that drops you at your destination but to enjoy the Keys you need your own vehicle. Take 836 West to Florida Turnpike South and follow this for 24 miles until it merges onto US 1 South at Mile Marker 126. On this highway you can pass through the entire length of the Keys. The green mile markers run west to east, with number 1 in Key West.
DIVING: Diving Adventures (001 305 509 1376); Rainbow Reef, with shops in Key Largo and Islamadora (Chesapeake Resort) is a top-notch recreational facility and PADI 5* IDC (www.rainbowreef.us); Silent World Diving, Key Largo, is a BSAC centre run by an English couple offering specialist wreck trips and can offer nitrox and technical dives (www.silentworldkeylargo.com); Strike Zone Charters, Big Pine Key (001 305 872 9863); Quiescence Dive Shop, Key Largo (www.keylargodiving.com).
WHEN TO GO: Year-round sunshine, but storms are more usual July-November.
FOR NON-DIVERS: Beaches, bars and restaurants; Turtle Hospital (www.turtlehospital.org); Mel Fisher Maritime Museum (www.melfisher.org); Florida Keys History of Diving Museum (www.divingmuseum.com); Florida Keys Eco-Discovery Centre, swimming with dolphins, sea-angling. The Underwater Music Festival at Looe Key Reef is usually in the second week of July.
FURTHER INFORMATION: www.fla-keys.com. Weather guide and Shipwreck Heritage Trail, floridakeys.noaa.gov/welcome.html