For serious fanatics.Where: Oakwood Leisure, Canaston Bridge, Narberth, Pembrokeshire. Open from today until 26 September, call 01834 891373.NemesisJustin Garvanovic, the founder of the European Coaster Club, waxes lyrical about Nemesis. Open from tomorrow until 31 October, call 01653 668287.MegafobiaYet another award-winning ride, but this one really is in its own league, thanks to the wooden structure. Stomach-churning, head-spinning; good family fun.Where: Flamingo Land Theme Park and Zoo, Kirby Misperton, near Malton, North Yorkshire.

WELCOME TO the world of theme park thrills. Here are the newest and best roller-coasters, rides and drops in Britain:

Bullet
Winner of the White Knuckle Ride Association’s Gold Award in 1993, this ride shoots passengers bullet-style to the top of the roller-coaster before launching them into a 360-degree revolution. Opening hours will be 10am-5pm and entrance will cost pounds 5 (pounds 7.50 from 11 May) for adults, free for children. Nobody can accuse this gallery of not being bang up to date.The new galleries of the National Maritime Museum, Greenwich, London SE10 (0181-312 6565) open on 31 March. In one corner of his large canvas, The First of England, a lager lout is lying drunk next to a crate of beer on the deck of a cross-Channel ferry.

“The Wolfson Gallery of Trade and Empire” features an emotive waxwork of an elegant 18th-century English lady taking tea beside a manacled black arm reaching out from a ship’s hold – a reminder of Joseph Conrad’s comment that imperialism “is not a pretty thing when you look into it too much”.”Art and the Sea” closes with a commission from a contemporary artist, the felicitously named Humphrey Ocean. In “The Bridge”, visitors can have a go on various vessel simulators: a Viking ship, a Victorian paddle-steamer or a Seacat. Meanwhile, “Rank and Style” presents costumes ranging from the first naval uniform in 1748 to the protective survival suit worn by Tony Bullimore during his dramatic rescue two years ago. By the end of the expedition, the sailors were apparently so hungry, they were reduced to eating their own shoes.The nearby array of famous explorers includes Columbus, Drake, Cook, and Scott, but curiously omits Richard Branson. Audio-visual displays help explain the water cycle and effects of rising sea levels.Side doors off the main hall give onto a series of smaller, specialist galleries. “Explorers” includes a display on John Franklin’s failed 1845 mission to find the Northwest Passage.

Here, peeping out from under a tarpaulin, is the rather creepy, blueish waxwork hand of one of the dead men, discovered in a frozen lifeboat at the North Pole. On a raised platform in the centre of the hall is a display on “The Future of the Sea”, designed with environmental issues in mind. A section of the hull from the Sea Empress, the tanker that came to grief off the coast of Wales, and a scary-looking eight-foot harpoon-gun from Norway are all part of the exhibit. Dotted around the main hall are landmarks from the sea – Suhaili, the yacht in which Robin Knox-Johnston in 1968 became the first person to sail round the world single-handedly, the optic from the Tarbet Ness lighthouse which flashes out at the street 24 hours a day, and the constantly revolving, eight-ton propeller from a Type23 frigate, punctured with tiny holes to make its turning quieter and less easily detectable by submarines. In the lobby, you come face to face with an installation by Lucy Blakstad, maker of the recent Naked series for BBC2.

Images of the 12 sites featured on the Radio4 shipping forecast are paired up with the sounds of the forecast being read out, a noise so mesmerisingly soothing that many people admit they can’t get to sleep without it.Inside the museum, the sheer scale of the glass canopy strikes you – at 2,500 square metres, it is the largest single-span glass roof in Europe – think King’s Cross station crossed with a greenhouse. The curators are savvy enough to realise that in this Disneyfied age, visitors expect dynamism rather than dust.
As you approach the impressively colonnaded front of the 19th-century building, you are lulled into a sense of the sea by hidden speakers which relay a live broadcast of the sounds of waves crashing on Chesil Beach. Theme-park touches abound – bold, eye-catching displays and clear explanations – but they haven’t cheapened this part of our national heritage so much as livened it up. Its curators have taken the wise decision to focus not so much on ships as the sea, the stage on which so much British history has been played out over the centuries. The newly-refurbished museum in Greenwich re-opens to the public on Wednesday. But with nearly pounds 20m (pounds 11m from the National Lottery and pounds 8.6m from sponsors) having been poured into 16 spanking new galleries at the museum, that image could soon be swept away.