Dive Atlas of the World. Jack Jackson

an average tidal range of around 5m (16ft), and buoyed by the Gulf Stream, a large amount of water moves along some 10,000km (6000 miles) of coastline around hundreds of named islands and thousands of lonely, rocky stacks and reefs.

       RESTRICTIONS ON DIVING ON MARITIME WAR GRAVES

      There is a small minority of divers who cannot resist disturbing wrecks and the temptation of removing brass and other artefacts. Diving on deep wrecks has been facilitated by the introduction of technical diving for recreational divers and this has worried those still living who are connected with many who lost their lives in this century’s maritime military conflicts and disasters. In an effort to give greater protection to maritime war graves and military wrecks against trophy hunting, 16 wrecks have been designated Controlled Sites – where no diving is allowed without a special permit.

      Most of the dives are far from convenient car parks, launching sites or towns and require considerable planning and backup. For that reason the bulk of the diving is carried out around a number of well-established commercial centres that have the combination of a good road and rail network, accommodation, slipways, air compressors and dive boats. Most coastal towns have dive clubs or at least dive club members. With these dive clubs you will experience more of the varied diving to be found. Over 60 per cent of all British diving takes place in Scottish waters.

      ORKNEY ISLANDS – SCAPA FLOW

      I am not the first to think the Orkney Islands are magical. Witness the standing stones and stone rings dotted all over the islands. Scapa Flow is the largest sheltered natural harbour in Europe and this is where the Home Fleet made its Atlantic base during the last two major world conflicts.

      Considered impregnable, the Bay of Scapa Flow, covering some 310 sq km (120 sq miles), is sheltered by a ring of protective islands. Situated 25km (15 miles) north of the Scottish mainland, access is by daily car ferry from Scrabster or by regular flight to Kirkwall airport from Edinburgh and Aberdeen.

      A prime target for aerial or naval attack, a system of defence was installed in the form of anti aircraft gun emplacements, submarine netting, vigilant patrols and the now-famous blockships. This is also where one of the largest concentrations of shipwrecks in the world is found – the scuttled German High Seas Fleet, dating from 1919.

       A shipwreck at Scapa Flow. Wherever the interior of a wreck is open to passing current, it quickly becomes covered in marine life.

      Most diving concentrates on the sunken German fleet, but the blockships lie in clearer water at the entrance to Burra Sound. The central location of the German fleet means there is little water movement, which is fine for scuba diving, but also tends to trap particulate matter in the water column, resulting in poor visibility. This reduces the awe of these massive ships as you can only see small sections at a time and it takes many dives to explore each shipwreck safely. However, there are many other shipwrecks and remains of the already salvaged fleet, such as gun batteries, so the diving does not have to be restricted to the High Seas Fleet ships. There is also the wreckage of a WWII German ship, the F2 4, a salvage barge nearby at Lyness and older ships such as HMS Roedean 5.

      Whatever your preferences, German High Seas Fleet has mystique and historical importance. The wrecks are an important part of the Orkneys’ naval heritage, having played such a significant part in its history. These ships are fortunately protected now. Their watery grave is no longer such a mystery to us, yet it is deep enough to deter those who take these ancient warhorses less seriously. The ships themselves are disintegrating at an alarming rate; bad visibility and wreckage can result in getting snagged if you are not careful; and the depth limitations are such that many divers each year succumb to decompression sickness (the bends). This results from staying too deep for too long and not taking enough time to return to the surface. The diving on the ships is perhaps some of the most advanced in Europe and only properly trained divers should attempt the German Fleet.

      This deep, formidable, cold, natural harbour has served the warring nations’ fleets for centuries. At present there are remains of three German battleships, four light cruisers, five torpedo boats (destroyers), a WW2 destroyer (F2), two submarines, 27 large sections of remains and salvage equipment, 16 known British wrecks, 32 blockships and two battleships (the Vanguard 3 and the Royal Oak 1), with a further 54 sections of unidentified wreckage.

      2 THE GERMAN LIGHT CRUISER

       BRUMMER

      The Brummer (a German light cruiser) was scuttled in 1919 at 58° 53’ 50”N, 03° 09’ 07”W. Built in the Vulcan shipyard at Stettin on the Baltic coast in 1914, she carried 360 mines and had a top speed of 34 knots. She displaced 4000 tons and was 138m (460ft) long.

      The Brummer is just one of four German light cruisers that were scuttled under the orders of Admiral Ludwig von Reuter in 1919. Through the descending gloom, the graceful arch of the sharp bows comes into view. Dropping to the stony seabed divers can gaze upwards in awe at this massive ship lying on her starboard side. The hull is festooned in Plumose Anemones (Metridium senile) and feather stars (Antedon bifida). From here divers swim along the now-vertical decking, past the forward 150mm (5.9in) gun and approach the superstructure, which has mostly collapsed. The central section of the ship was blasted apart by salvage divers. The stern, however, where the other 150mm (5.9in) gun can be found, is mainly intact. Maximum depth is 36m (120ft) and divers return to surface by the mooring buoy line.

      Conditions vary tremendously during the season. Visibility is generally poor and it is dark on the seabed. In the centre of Scapa Flow lights should always be used. Work-up dives should be undertaken before doing the deeper battleships. Photographers prefer the blockships at the entrance to Burra Sound, where the average depth is half that of the German warships; there is much more light; more interesting marine growth; and the water is much clearer as the tidal race at Burra Sound sweeps away all sedimentation particles. However, this also limits diving time on these wrecks and even that only at slack tide.

      European wax anemones, also known as snakelocks anemones (here Anemonia sulcata) live symbiotically with spider crabs, gobies and periclimenes shrimps.

      Due to strong current, visibility at the Gobernador Bories is good.

      On the night of 14 October 1939, 20 years after the German Fleet was scuttled, the 188 metre (600ft) battleship Royal Oak was lying at anchor in the sheltered bay of Scapa Flow in the Orkney Islands. Her duties were to protect Kirkwall and the British fleet from aerial attack. Scapa Flow was considered impenetrable because of the narrow passages between the reefs and islands. Attack was considered likely only from the skies. However, nobody told this to Günther Prien, commander of the U–47. He stealthily approached Scapa Flow, in what is considered by many to be one of the bravest feats in naval history and, at the dead of night, sank the Royal Oak. The Royal Oak is now a designated war grave and protected by law. Diving on her is strictly forbidden. As a result, she is the ship most divers want to visit.

      TOP TEN TIPS TO DIVING AT SCAPA FLOW

      Most of the diving