If your idea of surfing involves sitting in front of a television, you could do your body and soul a few favours by flicking the off button, getting up from the sofa and heading to the coast to try the real thing instead.

Of course, you might justifiably ask why anyone should want to surf the cold, grey waters of the British Isles, but the surf isn't always that unwelcoming: from May to October, it's just as likely to be bright and blue and, with a good wetsuit, it'll even feel warm(ish).

The search for waves will take you to some of the most beautiful stretches of coastline in Europe. Add to that the improved fitness to be gained from an aerobic work-out of paddling out through the waves, scrambling to your feet, riding the curl and being tumbled underwater by the inevitable wipe-outs, and you have two good reasons to surf in the UK.

But in order to make the most of Britain's fickle waves, you need to know where to go and when. All committed surfers can read an Atlantic weather chart and predict what the surf will be like days in advance, but there are several websites and phone numbers you can dial for a surf check (see below).

Once you know there's surf on the way, here are five of the best spots to head for, whether you're a complete beginner or the Silver Surfer.

Newquay
Crammed to the gills with egos and wannabes, and undoubtedly the most overhyped surf spot on this side of the planet, Newquay is still a good place to try the sport simply because the town has everything you need, from surf schools and shops with board hire, to several beaches with the most consistent waves in Britain.

The most favoured beach for beginners is Fistral, the venue for international surf contests, but other popular beaches include Towan, Great Western and the superbly-named Lusty Glaze.

The waves are always crowded but you'll see a high standard of surfing as some of Britain's best exponents of the sport are based in Newquay, and you'll also get to see the British surf scene at its most vibrant (or ridiculous, depending on your age and point of view).

Surf schools: West Coast Surfari (01637 876083) and Dolphin Surf School (07974 629381). There are no end of cafés close to the beaches and in the town, and popular surfer's pubs in Newquay include the Red Lion above Towan and the Sailor's Arms in Fore Street. If the surf isn't thrilling enough for you, there's shark fishing - yet another attempt by the locals to try to convince you that this is anywhere but Britain.

Llangennith, Gower Peninsula
A huge beach of golden sand that attracts everyone from complete beginners to experts. There's a surf school at the beach (the village of Llangennith is about half a mile inland) and the local surf shop is run by Welsh surf legend and former international competitor Pete Jones.

Llangennith is a mellow version of Fistral: less crowded, with a wide variety of surfers vying for the waves, and, in general, there's a friendly, laid-back atmosphere. The place seems to be particularly popular with students, especially during term-time when they pile in from nearby Swansea University.

When the waves aren't too big, the beach is ideal for novice surfers. However, during larger swells there are endless lines of white water to paddle out through, which even the fittest of surfers can have trouble negotiating. In these conditions, try one of the other beaches on the Gower that will have more manageable waves.

Surf schools: The Welsh Surfing Federation Surf School (01792 386426) operates from Llangennith. The King's Head in the village has good food and beer, and there's a café and shop at Hillend Caravan Park above the beach. Take time out from the waves to walk to the top of Rhossili Downs above the beach, from where there are great views of much of South Wales and across the Bristol Channel to Devon and Somerset.

Saltburn, Cleveland
The grey - okay, steel blue - waters of the North Sea are not the first place that springs to mind when you think of surfing, but the coast around the toytown village of Saltburn has some of the best and most challenging surf in Britain.

The beach has waves that are ideal for beginners and intermediates, breaking to the right of the old Victorian pier, while further south along the beach are a couple of more powerful breaks that are best left to more experienced surfers.

Travel north or south of Saltburn and you'll find some of the best reef and point breaks in the country but, true to the tradition of the sport, these "secret" spots can't be mentioned here, otherwise the locals will ensure I never surf again.

Surf schools: Saltburn Surf Shop (01287 625321) above the beach can provide both lessons and equipment, and aprés-surf food and drink are available from the Ship Inn and Bailey's. Just inland are the North York Moors, great for hiking or mountain biking, and a few miles down the coast is the attractive former whaling port of Whitby.

Portrush, County Antrim
I first surfed this stretch of coastline last year, and I was blown away by both the waves and the beauty of the area. The pretty beaches of West and East Strand at Portrush are ideal for all standards of surfer, and have a great backdrop in the form of Donegal's Inishowen Peninsula. West Strand also has a good reef break for experienced surfers, while in powerful swells East Strand is a heavy wave suitable for good surfers.

According to Andy Hill, of Troggs Surf Shop, the whole of the Causeway Coast has excellent and consistent waves and, if you time your visit right, it's unlikely you'd come away without enjoying a few quality sessions.

Surf schools: Troggs Surf Shop (02870 825476) is the biggest surf shop in Ireland, offers surf lessons and provides a local surf report on 09061 337770. The Hidden Cove next to the surf shop is a good place for an aprés-surf fry-up, and the Harbour Bar serves good food and beer. While in the area, take time to visit the amazing basalt columns of the Giant's Causeway, and maybe Bushmills Distillery, both just a few miles east of Portrush.

Thurso, Caithness
Castle Reef at Thurso (also known as Thurso East) is regarded as one of the best reef breaks in Europe. Despite the cold, peat-brown waters and fickle climate, adventurous surfers from all over the world arrive here to sample its famous wave.

This is for expert surfers only, breaking heavily over flat slabs of Caithness sandstone, but there are smaller waves on the nearby beach that less experienced surfers will enjoy.

The whole of the coastline of northern Scotland is pounded by waves, which vary from the reefs at Brimms Ness - even more challenging than Castle Reef - to the more mellow beach breaks around Durness. And, if it should go flat, there's plenty of magnificent coastline and mountain scenery to explore.

Aprés surf: For accommodation and food, try Sandra's Backpackers Hostel, Princes Street (01847 894575). A popular bar is Top Joe's on Trail Street, and if you find yourself in the area without a board and wetsuit you can hire basic versions of each from Harper's Fishing Tackle, 57 High Street (01847 893179). There is no surf-shop in the town though.

Top tips

· Look for a British Surfing Association Approved Surf School. Contact the BSA on 01736 360250 or e-mail colin@britsurf.demon.co.uk for more details.

· There are various premium-rate surf-check numbers, including Big G's (09003 406860 for Ireland; 406861, Scotland; 406862, NE England; 406863,S England; 406864 , N Devon & Cornwall; 406865, Wales).

· Websites, such as Pembrokeshire-based www.masimessurfhut.co.uk have both local surf reports and links to the rest of the UK and the world. Or you could call a surf shop in your chosen destination for the most up-to-date and accurate information of all.

· Wayne "Alf" Alderson is the author of Surf UK - the Definitive Guide to Surfing in Britain, published by Fernhurst Books at £14.95.