Cornwall has the advantage of hard rock geology sticking out into the Atlantic, so is usually a good prospect for underwater visibility, with some dramatic reefs and marine life.
There are also lots of wrecks, though fewer than there are further up the Channel.
With a north and a south coast, and sheltered areas like the east of the Lizard, there is usually somewhere to dive whatever the wind is doing. There are also plenty of sandy beaches for buckets, spades and sandcastles.
When the weather is bad enough to rule out diving, try the maritime museum at Falmouth, the seal sanctuary at Gweek or the Eden Project.
Cornish wrecks within sport-diving depth tend to be well chewed by the big waves of Atlantic storms. For something really unusual, have a look at the St Chamond off Hale.
This WW1 steamship was carrying a deck cargo of locomotives to run supplies to the trenches, so you can combine train-spotting with diving.
For scenic reef diving, the Manacles off the Lizard, Logan Rock by Porthgwarra, the Bucks by Lamorna Cove, and Longships and the Runnel Stone off Lands End are relatively accessible.
The Runnel Stone has the bonus of several wrecks, including the City of Westminster.
On a weeks holiday, you could aim to dive one of the more remote reefs, like the Seven Stones, Bann Shoal or Wolf Rock.
Wolf Rock is 10 miles south of Lands End, and is easy to find because there is a big lighthouse on top of it. It has been responsible for sinking many ships, including U-1209, but I have never seen any wreckage, except for junk beneath the small jetty.
On the north coast, cliffs are broken by sandy beaches with little inshore diving. Further out, Lundy Island offers good and relatively easy diving, with a sheltered side whatever the weather, and some very playful seals, featured elsewhere in this issue.
South Devon sees a transition from the big scenery of Cornwall to a softer shoreline of the English Riviera facing into Lyme Bay. Spectacular offshore reefs like the Eddystone and Hand Deeps are really the last traces of Cornish granite geology, despite being regularly dived from Plymouth.
A must-see wreck is HMS Scylla, sunk as the UKs largest artificial reef and the first specially cleared for divers. The project is managed by the National Marine Aquarium, a good day out in itself if diving is called off.
The nearby Liberty ship James Eagan Layne is also worth several dives, as much for the variety of cargo as the structure of the wreck. Both are also shallow enough for second dives.
East Devon and the English Riviera are home to a much higher density of wrecks, with hundreds in Lyme Bay, but visibility can suffer following heavy rain from the rivers that empty along the coast.
There are so many wrecks in the 30-50m range that it is impossible to list even a fraction. If youre into warships, the Royal Sovereign-class battleship HMS Empress of India is upside-down in 48m.
A popular easier wreck is the steamship Bretagne, in 32m. For a gentle scenic dive, there are caves and tunnels through the headland at the Parson and Clerk, between Teignmouth and Exmouth.
The Dorset coastline stretches from Lyme Regis to Christchurch. Softer geology means that, while there are scenic dives such as the East Tennants reef and Portland Bill, they are not as spectacular as those further west. A diving holiday from here on up the Channel is all about wrecks.
Lyme Bay is full of wrecks from collisions at sea, storms and two World Wars, particularly the first, and the vast majority are in comfortable depths for most divers.
A dive that attracts plenty of attention is the aircraft-carrying submarine M2. I prefer the steam dredger St Dunstan, a little further west at similar depth and with lots of big machinery.
The many dive boats of Weymouth and Portland often come this way, but there are also some closer wrecks sheltered by Portland Bill, and even in the harbour. There are also more further east, with the Aeolian Sky marking the overlap of range between dive boats from Weymouth and those from Poole.
This big modern freighter has plenty of engine-room and superstructure holes to explore, big shoals of pollack, and truck and Land Rover chassis among the cargo.
More firmly in the range of Poole dive boats is the wreck of the Kyarra, a torpedoed liner sunk off Anvil Point. If you dont want to spend the whole day out diving, nearby Swanage has several boats offering shuttle services to the Kyarra and other wrecks in the area.
Swanage Pier is also by far the best scenic dive in the area, and makes a good second dive or fallback in stormy weather. Closer to Poole, and often used as a quick second dive, are the remains of several Valentine DD tanks, foundered during testing of the amphibious drive systems later used on Shermans in the D-Day landings.
For a day off, the Tank Museum at Bovington has plenty more about DD tanks role in the Normandy landings.
WIGHT & HAMPSHIRE
The high spot of the diving here is all the wrecks off the back of the Isle of Wight, less visited than those in other areas.
The Warwick Deeping is a classic armed trawler with guns, ammunition and depth charges all still on the wreck. Nearby, the wreck of the ocean-going tug Witte Zee offers a similarly sized dive, but without all the armaments.
Inshore, the War Knight is a WW1 standard ship that sank in 12m and makes a good second dive, with boilers, turbine gearbox, masts and winch gear. Another inshore wreck on the back of Wight is the Louis, a steamship carrying munitions for the trenches. Plenty remains on the wreck.
In less co-operative weather, wrecks in the Solent offer fallback sites, though as with any estuary area visibility can be low, particularly after high rainfall.
To the east, sites overlap with those accessible from Sussex. The Mixon Hole is a very unusual scenic dive, a giant scour hole in the seabed with ledges full of marine life.
Inshore, the remains of a Mulberry harbour unit off Pagham make a shallow second dive.
On days off, divers are spoiled for choice, with the Shipwreck Museum on the Isle of Wight, the Submarine Museum at Gosport, including a hardhat diving gear display, and the Royal Navy Historic Dockyard at Portsmouth, with HMS Warrior, HMS Victory and the Mary Rose.
SUSSEX & KENT
With a long straight coastline from Wittering to Eastbourne broken only by a few headlands, the diving here is characterised by offshore wrecks at slack water.
In the western part of Sussex, the big dive is the armed merchant cruiser HMS Moldavia. Groups plan a weeks holiday to dive the Moldavia alone.
At more moderate depths, the steamship Gascony is upside-down in 30m, with gun carriages among the cargo. The armed trawler HMS Northcoates has guns and minesweeping gear at 30m. A little deeper, the steamship Basil is stacked full of ammunition at 40m.
The biggest concentration of wrecks in Sussex is off Beachy Head, with Brighton and Newhaven to the west and Eastbourne to the east.
The steamships Ashford and City Of Waterford at 41m and 36m are typical - upright, moderately intact and teeming with fish. Further east, the concentration of wrecks increases closer to Dover.
Unless you stay out for both slack waters, the difficulty with this stretch of coast is getting a decent second dive.
However, further east the funnelling effect of the Channel means that the shift of tides along the coast increases greatly, so travelling 10 miles could bring the next tide three hours closer, and make two slackwater dives possible.
The problem with diving holidays here is that charter-boats are few and far between. But if you have access to a boat there are plenty of wrecks, with some real gems.
There are also fantastic sandy beaches for group members who would rather be building sandcastles.
East Anglia benefits from funnelling tides, similarly to Kent. Two slackwater dives can be as close as three hours apart with a 10-mile boat ride between them. Visibility can be poor, but is usually good enough in the summer.
Off Norfolk, the submarine HMS Umpire is at just about the right state of decay to show all the detail of the engineering while remaining a recognisable submarine wreck.
Another interesting sub is UC70, a German minelayer sunk further north off Whitby, in 27m.
The North Sea is filled with shifting sand and gravel banks, so there are opportunities for reasonably shallow wrecks well offshore.
For a very different kind of wreck, the lightship LV83 can be found upright and very intact on the Dogger Bank, resting in 34m with the light tower reaching up to 20m.
For days off, there are maritime heritage centres and museums, drawing on the fishing and shipbuilding industries of the past, as well as The Deep aquarium in Hull.
NE ENGLAND & SE SCOTLAND
Diving opportunities increase as we get further north in the North Sea. Seahouses serves as home for many boats taking divers to the Farne Islands and wrecks along the coast.
Across the border, Eyemouth, St Abbs and North Berwick are home to dive boats ranging as far as the Firth of Forth, which is also covered by boats operating from the northern side of the estuary.
The geology becomes more conducive to good scenic dives, and visibility is usually good until you venture too far into the Forth. The Farnes are also home to seals, which will come to play with divers.
To the south of Seahouses, the Somali has a great blend of structure and cargo to explore at 30m. Among the Farnes, the Britannia and Chris Christensen lie close to the rocks, so a 30m wreck dive can continue onto a scenic wall with anemones and dead mens fingers, then into the shallows to play with the seals.
For those with no boat, there are top-class shore dives, particularly off the harbour wall at St Abbs, where Big Green Carr and Cathedral Rock are just the highlights of an extensive reef system.
From a boat, there are big canyons and caves at Wuddy Rocks and off St Abbs Head. Many of the coastal wrecks of the area lie among big rocks, like the steamship Glanmire in 30m.
Sandy beaches continue north, but become more rocky from Eyemouth onwards. On a day off diving, there are imposing castles to tour, or visit Edinburgh to see the Royal Yacht Britannia.
NORTH OF SCOTLAND
This area instantly evokes in divers thoughts of Scapa Flow and the scuttled German fleet from WW1. Its a great diving-holiday destination, and well set up for those travelling light, with cylinders and weights provided on most boats.
But there are other options on the mainland.
A little closer to the south are the Moray Firth wrecks, which include the impressive 5995-ton tanker San Tiburcio. Split in half and 413 ft long, it is 35m to the seabed and 25m to the main deck on the forward section.
Also within comfortable depths are the T-Class submarine HMS Tantivy in 38m and the yacht/ patrol-boat Verona in 39m.
Just out of Lossiemouth is the steel trawler Unity in 24m. The famous Moray Firth dolphins often wait outside the harbour and ride the bow of the dive-boat out to the wreck.
On a day off diving you can still see the local fish life at the Macduff Aquarium - and there is even a rocky shore dive right in front of it.
There is an enormous variety of diving from the mainland to St Kilda, from the Summer Isles in the north to the Clyde and approaches in the south.
Accessed by boat from the mainland at Ullapool or Little Loch Broom, the Summer Isles have a scattering of wrecks and enough scenic dives to occupy a weeks holiday. Close to shore and not to miss is the trawler Fairweather V, upright, intact and covered in plumose anemones in 25m.
Further out, a newer wreck is the freighter Jambo, overturned in 31m with swim-throughs beneath the deck. Nearby, an unusual scenic dive is Conservation Cave, half submerged and packed with small plumose anemones.
The far west coast of Skye is home to the steamship wrecks Doris and Chadwick, both well broken but with plenty to see, and colourful marine life in typically clear water. There are many fine scenic dives, including An Dubh Sgeir, where a wall and crevice are decorated with every kind of anemone, and are home to critters from crabs to conger eels.
On the way to Skye, dont miss out on the fantastic Port Napier, a mine-laying steamship that rests with its port side breaking the surface of the Kyle of Lochalsh.
The busiest diving location is Oban, with dive boats visiting wrecks locally and through the Sound of Mull as far out as Tiree, and liveaboards venturing all the way to St Kilda.
A good start is the WW2 wreck of the Breda. Upright with stern in 30m and bow rising to 12m, the Breda is pretty intact, with holds full of cargo from truck parts to army boots.
Among the Sound of Mull wrecks, the steamship Hispania is one of the favourites. Resting intact on a slope with stern at 32m and bow deck at 16m, it crosses the current and is covered in anemones. The cargo has been salvaged, but that just makes space to travel from stern to bow inside the wreck.
For scenic dives, Calve Island by Tobermory has a wall that stretches from just below the low-water mark to below 50m.
On a non-diving day, my recommendation would be to tour one of the whisky distilleries found throughout the region. On second thoughts, make that at least two non-diving days.
Holiday diving in Wales is essentially based on the two outer corners, Anglesey in the north-west and Pembrokeshire in the south-west. Both regions are home to good collections of wrecks and some big currents, with marine life to match. Visibility can vary from good to awful, especially after heavy rainfall.
To the north of Anglesey, the steamship Vigsnes stands in 40m with all the anti-aircraft armament fitted to ships in WW2. South of Anglesey, the mussel-dredger Segontium stands intact in 31m.
Inshore, the tanker Kimya makes a great second dive, as its bow breaks the surface at low water.
In Pembrokeshire, the wreck everyone wants to dive is the Lucy on the north side of Skomer Island. For a scenic dive, this side of Skomer also offers walls stretching all the way to the Garland Stone.
Shallower dives are the steamships Dakotian and Behar, both sunk in WW2 by mines in Milford Haven, so well sheltered from foul weather. Vis on these is usually best towards the top of an incoming tide.
Pembrokeshires other big headland is St Davids, with scenic diving round Ramsey Island and the Bishops and Clerks. Small wrecks can be found close in all along the coast, including the paddle-steamer Nimrod and the steamships Vendome and Musgrave (this months Wreck Tour).
Dive boats also range further north into Cardigan Bay, where a must-see wreck is the Cold War frigate HMS Whirlwind, capsized in just over 30m.
We have already mentioned Scapa Flow and the Isle of Wight, but opportunities for an overseas holiday within the UK, where the currency remains the pound sterling, does not end with Hampshire or the Orkney Islands.
Further north we have Shetland, then, across the Irish Sea the Isle of Man and Northern Ireland. From the southern part of Britain, an overseas holiday could be based on the Isles of Scilly or the Channel Islands. Off the West Coast of Scotland, it can be hard to define where overseas really starts, there are so many islands in the Inner and Outer Hebrides, some reached by bridges and others by ferries.
Well be looking at some of these overseas locations in future issues. Of course, if youre a diver who lives in one of these locations, a diving holiday to the mainland is an overseas holiday.
Never dived in the UK
By all means plan a weeks holiday, but make sure you get into UK diving gently. You may have heard it is rufty-tufty, but in reality much UK diving is fairly easy and not that strenuous once you get the hang of it.
A few gentle warm-up dives with an experienced UK diver or instructor should get you settled in at the start of your holiday, or take a weekend or two beforehand with your local dive centre or club.
The amount of wetsuit and weights needed is not that different to that required in winter in the northern Red Sea, Mediterranean or Canary Islands. The suits are just that bit bulkier, with a little more weight on the belt.
The main difference is that variable visibility and currents mean that buddy pairs rely more on each other and less on a dive guide.
UK dive centres will not give you the services of an in-water guide unless you request this. So if you want fully guided dives, do check when you book.
What about gear
When diving on an overseas holiday, tanks and weights are nearly always inclusive, and the dive centre or boat will usually have a good selection of other kit available to rent.
The tradition in the UK is that divers bring their own equipment, so tanks and weights are rarely included and may not even be available.
Availability of other rental kit varies greatly. Some dive centres have big stocks, some a few sets, others nothing. So if you need to rent anything or everything, check before you book.
If your centre or boat doesnt have what you need, it may be able to arrange to get it. But if it cant help, dont be deterred. One of the great things about staying in the UK for a diving holiday is that airline baggage allowance is no longer a restriction. Rent some kit from your local dive centre and take it with you.
Why not look at buying If you add up typical rental costs, after a week or two of renting kit you may find that you could have bought it secondhand or even new for a similar price.
Now is the time to browse Dive Shows, small ads, eBay and the special offers at dive shops and online, as divers and dive centres buy new kit for the new season, so the used kit or last seasons comes up for sale at bargain prices.
Where to stay
Most dive centres and boats have arrangements with local lodgings at diver-friendly budgets. Quite a few even have their own B&B or bunk-room accommodation.
Having said that, whether you want to go upmarket to a 4* hotel, or downmarket and camp, there is usually plenty of choice.
If you are holidaying with non-diving family or friends, a static caravan or holiday cottage can be a good choice.
With UK holidays you do need to be flexible to avoid the worst vagaries of the weather - so try to ensure that your hotel, guest house or other accommodation can be flexible too.
What about the weather
Divers, dive centres and skippers complain that the weather for UK diving last season was atrocious, yet I lost only three days on location due to poor weather. That was a bad season for me. The year before, I lost only one day.
The key to getting good diving despite the foibles of UK weather is flexibility.
Can you keep you holiday dates flexible, and can your dive centre or skipper be flexible to fit in with the weather That way, if a massive gale is forecast to blow in from the Atlantic, you can delay a few days, or re-schedule. We often get the best visibility when the sea has calmed down a few days after a big blow.
Can you be flexible about dive sites Many regions have alternatives that provide sheltered conditions, as long as youre inshore. It may need to be with a different dive centre or a self-contained shore dive, but opportunities usually exist, if only you do a bit of research and make contingency plans before you go.
Even if the alternative dive is uninspiring, it can be an excuse for practising drills. Worst case: where is the closest inland diving site