Dive Atlas of the World. Jack Jackson
Чтение книги онлайн.
Читать онлайн книгу Dive Atlas of the World - Jack Jackson страница 17
Название: Dive Atlas of the World
Автор: Jack Jackson
Издательство: Ingram
Жанр: Спорт, фитнес
isbn: 9781607653622
isbn:
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 in Scapa Flow is potentially dangerous and virtually all the German Fleet wrecks should be treated as decompression dives. Not only does this put undue stress on the diver, it considerably reduces the time to be spent in the water and the ultimate enjoyment of the wrecks. Most divers are attracted to the ‘technical’ side of deep diving. However, the larger battleships are not only in very deep water, they are all upside down, boring and, unless you want to spend your entire dive on the underside of a ship’s hull, they can be dangerous to explore any further.
Royal Navy Divers and a few civilians perform an annual memorial dive on the War Grave of HMS Royal Oak and replace the flag.
■ Attend a deep diving course with a recognized training agency.
■ Buy and learn how to use, not only a computer, but also standard air decompression tables – and never trust either.
■ Never use your computer ‘to its limit’, always stay within the safety margin.
■ Increase depth slowly for acclimatization.
■ Recognize symptoms of nitrogen narcosis.
■ When symptoms of narcosis appear, ascend immediately until symptoms are relieved.
■ Dive only with experienced deep divers.
■ Be Safe; do not put yourself or others at risk.
■ Plan your dive and dive your plan accordingly, with no open-water decompression stops, use the wreck marker buoy lines for ascent and descent.
■ Always obey the dive boat captain.
6 CATHEDRAL ROCK
ST ABBS AND EYEMOUTH MARINE RESERVE
Cathedral Rock is at Lat 550 53' 55"N and Long 020 07' 29"W. Better still, invest in Ordnance Survey Pathfinder 423 Map sheet NT 86 / 96 G.R. 922 673. Admiralty chart No.160.
At the opposite end of Scotland, on the extreme southeast coast, is Scotland’s only marine reserve, founded by Lawson Wood. First discovered in the 1950s, Cathedral Rock is the most popular dive site within the St Abbs and Eyemouth Voluntary Marine Nature Reserve and possibly one of the most dived in the whole of the British Isles.
Many divers often fail to find the site, relying on poor information, inadequate navigational skills or, more often than not, are just enjoying themselves so much off St Abbs harbour wall, that they never get as far as Cathedral Rock. The rock is part of the reef which runs perpendicular to the corner of St Abbs harbour wall, known locally as Thistly Briggs. The rock is never visible, even at the lowest of tides and many divers mistake a reef close by for Cathedral Rock. Underwater, the wall falls away and is deeply undercut with eroded horizontal strata lines, now filled with squat lobsters and Leopard Spotted Gobies. Comprising two chambers, the top tunnel is known as the Keyhole. Although it is easily negotiated, exhaust air can become trapped and kill marine life, therefore it is best not to linger in this area. The lower tunnel archway is massive, of double-decker bus proportions, with a stony bottom directly under the arch and a tumble of boulders on each side. The walls and the roof of the arches are festooned with a dwarf species of the Plumose Anemone (Metridium senile) as well as sponges, soft corals (Dead Men’s Fingers), mussels and hydroids. Small schools of pollack are often herded into this natural arena by predatory cod. For Photographers there are panoramic vistas of the archways, diver portraits, diver interaction shots and the staggering amount of macro work on nudibranchs, crabs and molluscs.
7 THE WRECK OF THE LUSITANIA
by Jack Jackson
The 232m (762ft) Cunard luxury liner RMS Lusitania was the largest and fastest vessel of her time plying the Atlantic route. She was torpedoed 19km (12 miles) south of Ireland’s Old Head of Kinsale by the German submarine U-20 at 02:10 hours on 7 May 1915 and sank in 18 minutes. More than 1200 of the 1257 passengers and 702 crew died. The fact that she was a passenger ship and that the dead included 123 Americans, 291 women and 94 children, had much to do with America entering World War I in 1917.
The wreck was first dived in 1935 by Jim Jarrett using a forerunner of the armoured one-atmosphere diving suit. The Royal Navy dived her in 1954 and in the late 1960s. In the early 1970s John Light, an American naval diver who then owned the wreck, dived her several times with limited bottom times. In 1982, using Heliox and a diving bell, her anchors and three propellers were recovered. In 1993 the locator of the Titanic, Robert Ballard, surveyed her with submersibles and Remotely Operated Vehicles.
ARGON
Technical divers using dry suits often use argon gas for suit-inflation to help maintain body temperature. Denser than air and much denser than helium, argon acts as a better insulator for retaining body heat, while inflating the suit enough to eliminate body-squeezes.
The argon is carried in a separate small cylinder, but it is particularly important to make sure that only the correct inflation hose is connected between the cylinder and the dry suit so that the gas cannot be breathed by mistake. Some divers use a standard regulator, which still has a regulator second stage attached, as well as a suit-inflation hose. The argon cylinder does not contain any oxygen, so if the diver switched to the wrong second stage by mistake, the result would be fatal.
The first visit by recreational technical divers was in 1994 when eight Britons, led by Polly Tapson, were joined by deep-wreck diving expert Gary Gentile and three of his friends from the East Coast of America. The Lusitania was dived again in 1995, 1999 and in 2001 by a Starfish Enterprise team led by Mark Jones. They worked with current owner Gregg Bemis on an archaeological survey as a precursor to raising and conserving artefacts. The wreck lies on her starboard side with the bow in good condition and draped in lost trawl nets. The stern is still recognizable as part of the ship but the middle section is badly broken up.
Ceramic floor tiles in one of the bathrooms of the RMS Lusitania.
A СКАЧАТЬ