Scapa Flow missing divers feared dead TWO divers are feared dead after failing to surface while on a dive of a WWI German warship in Orkney's famous Scapa Flow. Police divers have been called in to help in the search for the missing unnamed men, aged 62 and 58, from Holland. Both divers, understood to have been experienced and qualified instructors, had failed to surface from the wreck of the German battleship, SMS Brummer - one of 52 which famously scuttled seven months after the end of the First World War. Scapa Flow is a major draw for divers around the globe - attracting around 4,000 to the islands and boosting the economy by an estimated £3.5million a year - with seven of the German wrecks still on the seabed. The British battleships Royal Oak and Vanguard are also war graves in the same stretch of water. Both of the missing men had been aboard the dive vessel Crusader, operated by the Scapa Flow Diving Centre, but failed to surface at 4.20pm on Tuesday. The Stromness lifeboat was launched to take part in a search about one-and-a-half miles North of Cava. The Shetland-based Coastguard search and rescue helicopter was also on the scene shortly afterwards. The search was suspended at 8.20pm, due to failing light, but resumed early on Wednesday morning. Specialist Scotland Police divers based in Aberdeen also arrived to carry out underwater searches. A police spokesman said: "The missing divers have not yet been located and there are serious concerns for their well-being. We can confirm they are foreign nationals. There is an average of between one to two diver deaths a year at Scapa Flow, although there were four in 2004. The latest before this week was a 66-year-old man from Holland who died last September while diving at the wreck of the SMS Dresden. He was not named. Safety Graeme Forsyth, National Coach for the Scottish Sub Aqua Club, said that, while he had no information about the latest incident, it should be remembered that thousands safely enjoy diving at Scapa Flow each year. He said: "There are very few weeks in the year when there aren't diving parties up there. With the wrecks of the German fleet, it really is a Mecca for divers from around the world, making it important to the Orkney Islands. He added: "Diving around Scotland is comparatively safe. There are a lot of rules and regulations and if these are adhered to it is a relatively safe activity. But sometimes there can be medical reasons for divers getting into trouble. If somebody becomes unwell under water there is usually nobody there to help or if there is there is not a lot that can be done. If somebody collapses in the street an attempt can be made to resuscitate them and get an ambulance, but it is different when somebody is diving. SMS Brummer is one of seven German WWI ships still left in Scapa Flow after the fleet scuttled in 1919. The Brummer was one of a 74-strong fleet of ships of the German High Seas Command which had to surrender for internment at Scapa Flow as part of the Armistice agreement in 1918. On 21 June, 1919, under the mistaken belief that peace talks had failed, the fleet commander, Rear Admiral Ludwig von Reuter, gave the order to scuttle the entire fleet. A total of 52 ships were sunk to the seabed, and the event remains the greatest loss of shipping ever recorded in a single day. The majority of the German ships were raised in one of the largest ever salvage operations in history and only seven of them remain, although evidence of the others can still be found by divers. The seven German wrecks that remain are scheduled under the Ancient Monuments and Archaeological Areas Act 1979. Meanwhile, the British battleship Vanguard was sunk in an accidental explosion in 1917, killing all but two of the 845 men on board. In 1939 HMS Royal Oak was torpedoed, drowning 833. Both are now war graves that may not be dived.