Taking the plunge in British waters may be a different experience to diving in tropical seas but it rewards divers and snorkellers with historic wrecks, reefs covered with soft corals and scuttling crustaceans. Dive schools offer a good way to get a first taste – and snorkelling is available for everyone who can swim. For certification, many dive schools do the theory part of the training in advance online, completing the skills component in person over a few days – a good way to combine certification and a UK holiday.

Scapa Flow, Orkney

This body of water, one of the largest natural harbours in the world, is home to dozens of wrecks from the first and second world wars, including the scuttled German first world war fleet, a legacy of Scapa Flow’s time as a naval base. While experienced divers will get the most of out of the area (try Huskyan’s seven-day dive/stay packages, from £685pp), beginners can enjoy a taste of the action via shore dives on the Churchill Barriers, structures built in 1940 to block eastern approaches to the harbour, and the scuttled ships that preceded their construction. Kraken Diving, Scapa’s only dive school, offers guided dives here, as well as guided boat diving for those with more experience. Snorkel safaris are also available.
• Guided dives with Kraken from £170, try dives £90, snorkelling £60pp; full equipment hire from Scapa Scuba £60 a day, air refills from £4

Swanage pier, Dorset

The shallow water beneath this late-Victorian pier teems with life, from edible and spider crabs to brightly coloured cuckoo wrasse, bream and cuttlefish. At just five metres deep, it offers easy diving conditions for beginners, but there’s plenty for more experienced divers, especially those into photography, who’ll appreciate the chance to get up close to the local marine life. Divers Down runs courses and hires out equipment from its shop on the pier, as well as operating two charter boats for trips out to wrecks. Some, such as the Fleur De Lys, a French crabbing boat that sank at 13 metres in 2000, are suitable for beginners to explore.
• Full equipment hire £60, air refills from £5, pier diving £1.50pp, local boat dives from £35pp

Porthkerris, Cornwall

Hundreds of ships were dashed to pieces over the centuries on the Manacles and other submerged rocks that line this side of the Lizard peninsula. Many are easily reached on full- or half-day boat trips and many are fairly shallow, which not only increases the likelihood of visibility being good but also makes them accessible for less experienced divers. There’s good shore diving and snorkelling, with Porthkerris Divers, whose protected house reef is home to anemones, sea cucumbers, sponges, sea urchins, crustaceans, cuttlefish, lots of species of kelp and all manner of fish. You just walk into the water from Porthkerris Beach. Portkerris Divers also runs courses.
• Full equipment hire from £35, air fills from £5, boat dives from £30 per dive, unlimited shore dives £5pp, escorted dives from £40

Lundy, Devon

A familiar name to shipping forecast listeners, this island off the coast of north Devon is known for its birdlife, but there’s a huge amount going on beneath the waves too. The island’s resident population of Atlantic grey seals is the main attraction – these inquisitive creatures are used to humans and it’s not uncommon to find them tugging playfully at divers’ fins. Ilfracombe-based Easy Divers hires gear and runs regular day trips for divers and snorkellers. The dive season runs from May to September.
• Two guided dives with full equipment hire £177pp, snorkelling equipment and boat trip £132pp

Farne Islands, Northumberland

Weather-permitting you can dive year-round on the east coast, though the best time of year for interactions with the grey seals that make this their home is late summer and into autumn, before the start of the breeding season. The diving is spectacular whether or not you get to play with the seals, thanks to the sheer rock faces that characterise the underwater world of the Farne Islands. Crevices in these walls abound with lobsters, shrimp and edible crabs, as well as soft corals, nudibranchs (sea slugs) and anemones. There are plenty of shallow, protected sites here for beginners; nervous newbies will get the most out of the area by hiring the services of a local divemaster as a guide. Boats depart from Seahouses.
• Day’s diving (two dives) with Billy Shiel’s Boat Trips £50pp, air refill £6, day’s diving with full equipment £150pp, guiding £50

Stony Cove, Leicestershire

There’s been diving at this flooded quarry since 1960, though a lot has changed at the site since local scuba pioneers first started exploring here. Today, you’ll find a range of sunken vehicles to explore, including an aeroplane cockpit, a helicopter, an Elizabethan merchantman and a bus, all positioned in terraced dive areas that are graded to reflect difficulty. It’s open for diving and snorkelling 362 days a year, with averages temperatures ranging from 18C in August to 4C in March. For the best visibility – up to 20 metres – visit between the end of October and Christmas. Night diving – yes really – is available on the first and third Wednesday of the month. Dive training courses run regularly at weekends, with additional midweek courses laid on, on demand, if at least two people are booking.
• Full equipment hire £48.20, diving £25pp, snorkelling £8pp, stoneycove.com

Basking sharks, north Cornwall

The world’s second largest fish – basking sharks can grow to up to 12 metres long – comes to the south and west coast of the UK each year, timing their arrival with the spring and summer plankton blooms. They arrive in Cornwall and continue their journeys north as far as John o’Groats. The best way to experience these creatures in the water is snorkelling rather than diving, as they mainly feed just beneath the surface. Newquay-based Atlantic Diving runs three-hour snorkel safaris throughout the summer (the main shark spotting season is May to July but they continue to appear as late as October), putting on a boat whenever local fishers report seeing sharks. As such, advance booking isn’t possible – you’ll need to phone for availability (details on website). Atlantic Diving also runs dive trips to the more than 200 wrecks in the area.
• Snorkel safari including snorkelling equipment and wetsuit £90pp

St Abbs and Eyemouth Voluntary Marine Reserve, Berwickshire

Tiny white sea stars, sea urchins and a type of soft coral known as dead man’s fingers, cover the rocks all along with patch of protected coastline, while lobsters stare out from crevices and flat fish hide themselves in the sand on the seabed. Dive companies running boats out of the small harbours at St Abbs and Eyemouth include DiveStay (half a day diving from £45pp) but you’ll need to bring your own gear. Not to worry if that’s not an option because Snorkel Wild runs small guided snorkelling trips (two to four people, £30pp, equipment hire £10) that explore Coldingham Bay and its surroundings. Perfect for families, with kids as young as six able to take part if accompanied by an adult.

Isle of Portland, Dorset

There are dozens of wrecks to dive off Portland, from submarines to paddle-steamers, with something for divers of all experience levels. A boon of Dorset diving, particularly for those combining diving with other holiday pursuits, is the fact that you can pop out for a single dive and be back at the harbour within a couple of hours, rather than spending all day out on a boat. There’s plenty to explore in and around the harbour, with drift dives offering a thrilling way of seeing a large area in a short space of time. Local operator Dive Beyond runs boat charters and courses for all levels, as well as hiring out equipment – its online booking process is one of the more streamlined available.
• Full equipment rental from £40, air fills £5, shore dives from £25pp, boat dives from £32pp

Holy Island, Anglesey

The squiggly coastline between Porth Dafarch and Trearddur Bay has beaches that are seemingly made for easy walk-in, walk-out shore diving and snorkelling. Their shallow, protected coves are untroubled by currents and allow you to serenely explore underwater gullies that are a haven for ballan, cuckoo and corkwing wrasse and, if you’re lucky, dogfish. SBS Rib Charter runs short boat rides out to Holy Island’s wrecks and reefs, several of which are suitable for beginners. You’ll need to bring all your own gear as there’s nowhere nearby that hires it.